Last active
January 12, 2017 02:03
-
-
Save mwachs5/aaf48637e1189ba86b93113263c926b9 to your computer and use it in GitHub Desktop.
Freedom E300 Code for Driving a 32x16 RGB LED Matrix
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
// See LICENSE for License Details. | |
// These are the the generic snippets of Tim Newsome's Debug Demo code, necessary | |
// for driving a 32x16 RGB LED Matrix. | |
// The code sets up the PWM0 to deliver periodic timer interrupts during which the display is driven. | |
// This gist does not include the code to populate the actual images you want to display. | |
#include "plic_driver.h" | |
#include "platform.h" | |
#include "encoding.h" | |
static volatile unsigned int time_ms; | |
enum { | |
HIFIVE1_0, | |
HIFIVE1_1, | |
HIFIVE1_2, | |
HIFIVE1_3, | |
HIFIVE1_4, | |
HIFIVE1_5, | |
HIFIVE1_6, | |
HIFIVE1_7, | |
HIFIVE1_8, | |
HIFIVE1_9, | |
HIFIVE1_10, | |
HIFIVE1_11, | |
HIFIVE1_12, | |
HIFIVE1_13, | |
HIFIVE1_14, | |
HIFIVE1_15, | |
HIFIVE1_16, | |
HIFIVE1_17, | |
HIFIVE1_18, | |
HIFIVE1_19, | |
}; | |
static const uint32_t pin_mask[] = { | |
1<<16, | |
1<<17, | |
1<<18, | |
1<<19, | |
1<<20, | |
1<<21, | |
1<<22, | |
1<<23, | |
1<<0, | |
1<<1, | |
1<<2, | |
1<<3, | |
1<<4, | |
1<<5, | |
~0, // not connected on HiFive1 | |
1<<9, | |
1<<10, | |
1<<11, | |
1<<12, | |
1<<13 | |
}; | |
// LED display pins. | |
#define PIN_R1 pin_mask[HIFIVE1_2] | |
#define PIN_G1 pin_mask[HIFIVE1_3] | |
#define PIN_B1 pin_mask[HIFIVE1_4] | |
#define PIN_R2 pin_mask[HIFIVE1_5] | |
#define PIN_G2 pin_mask[HIFIVE1_6] | |
#define PIN_B2 pin_mask[HIFIVE1_7] | |
#define PIN_A pin_mask[HIFIVE1_8] | |
#define PIN_B pin_mask[HIFIVE1_9] | |
#define PIN_C pin_mask[HIFIVE1_10] | |
#define PIN_CLK pin_mask[HIFIVE1_11] | |
#define PIN_LAT pin_mask[HIFIVE1_12] | |
#define PIN_OE pin_mask[HIFIVE1_13] // active low | |
#define PIN_BLINK pin_mask[HIFIVE1_19] | |
// In the frame buffer, we store 4 bits each for R,G,B,A. | |
#define RED_OFFSET 12 | |
#define RED_MASK 0xf | |
#define GREEN_OFFSET 8 | |
#define GREEN_MASK 0xf | |
#define BLUE_OFFSET 4 | |
#define BLUE_MASK 0xf | |
#define ALPHA_OFFSET 0 // alpha 0: completely transparent | |
#define ALPHA_MASK 0xf // alpha 0xf: completely opaque | |
#define RED(pixel) ((pixel >> RED_OFFSET) & RED_MASK) | |
#define GREEN(pixel) ((pixel >> GREEN_OFFSET) & GREEN_MASK) | |
#define BLUE(pixel) ((pixel >> BLUE_OFFSET) & BLUE_MASK) | |
#define ALPHA(pixel) ((pixel >> ALPHA_OFFSET) & ALPHA_MASK) | |
// On the LED Matrix, each pixel is 16 bits. | |
// The top 5 bits are red, the middle 6 bits are green, | |
// the bottom 5 bits are blue. | |
#define FRAME_W 32 | |
#define FRAME_H 16 | |
static uint16_t buf0[FRAME_W * FRAME_H]; | |
static uint16_t buf1[FRAME_W * FRAME_H]; | |
static uint16_t *frame_buffer; | |
static uint16_t *draw_buffer; | |
static volatile unsigned int vsync_status; | |
static plic_instance_t g_plic; | |
// This can't be in flash for performance reasons. | |
uint8_t duty_cycle[16] = { | |
// Map color intensity to perceived intensity The number here is the | |
// duty cycle for each of 16 intensities, up to 63. | |
0, | |
1, | |
2, | |
3, | |
4, | |
5, | |
6, | |
8, | |
9, | |
13, | |
17, | |
22, | |
29, | |
38, | |
49, | |
63 | |
}; | |
static void drive_display() | |
{ | |
static unsigned int counter = 0; | |
static unsigned int phase = 0; | |
int address = counter & 7; | |
uint32_t basebits = 0; | |
if ((time_ms / 500) & 1) { | |
basebits |= PIN_BLINK; | |
} | |
basebits |= PIN_OE; | |
if (address & 1) basebits |= PIN_A; | |
if (address & 2) basebits |= PIN_B; | |
if (address & 4) basebits |= PIN_C; | |
GPIO_REG(GPIO_OUTPUT_VAL) = basebits; | |
uint32_t color; | |
for (int x = FRAME_W - 1; x >= 0; x--) { | |
color = 0; | |
uint16_t top_pixel = frame_buffer[(15-address) * FRAME_W + x]; | |
if (duty_cycle[RED(top_pixel)] > phase) color |= PIN_R1; | |
if (duty_cycle[GREEN(top_pixel)] > phase) color |= PIN_G1; | |
if (duty_cycle[BLUE(top_pixel)] > phase) color |= PIN_B1; | |
uint16_t bottom_pixel = frame_buffer[(7-address) * FRAME_W + x]; | |
if (duty_cycle[RED(bottom_pixel)] > phase) color |= PIN_R2; | |
if (duty_cycle[GREEN(bottom_pixel)] > phase) color |= PIN_G2; | |
if (duty_cycle[BLUE(bottom_pixel)] > phase) color |= PIN_B2; | |
GPIO_REG(GPIO_OUTPUT_VAL) = basebits | color; | |
GPIO_REG(GPIO_OUTPUT_VAL) = basebits | color | PIN_CLK; | |
} | |
GPIO_REG(GPIO_OUTPUT_VAL) = basebits | color | PIN_LAT; | |
GPIO_REG(GPIO_OUTPUT_VAL) = basebits & ~PIN_OE; | |
counter++; | |
if ((counter & 7) == 0) { | |
vsync_status = 1; | |
phase += 1; | |
phase &= 0x3f; | |
} | |
} | |
/* Entry point for PLIC interrupt handler */ | |
void handle_m_ext_interrupt() | |
{ | |
plic_source int_num = PLIC_claim_interrupt(&g_plic); | |
switch(int_num) { | |
case 0: | |
break; | |
case INT_PWM0_BASE: | |
drive_display(); | |
PWM0_REG(PWM_CFG) &= ~PWM_CFG_CMP0IP; | |
break; | |
case INT_PWM1_BASE: | |
time_ms++; | |
PWM1_REG(PWM_CFG) &= ~PWM_CFG_CMP0IP; | |
break; | |
} | |
PLIC_complete_interrupt(&g_plic, int_num); | |
} | |
static void setup_gpio() | |
{ | |
uint32_t outputs = PIN_R1 | PIN_G1 | PIN_B1 | | |
PIN_R2 | PIN_G2 | PIN_B2 | | |
PIN_A | PIN_B | PIN_C | | |
PIN_CLK | PIN_LAT | PIN_OE | PIN_BLINK; | |
GPIO_REG(GPIO_OUTPUT_EN) = outputs; | |
PWM0_REG(PWM_CFG) = 0; | |
PWM1_REG(PWM_CFG) = 0; | |
PWM2_REG(PWM_CFG) = 0; | |
} | |
static void setup_timers() | |
{ | |
PLIC_init(&g_plic, PLIC_BASE_ADDR, PLIC_NUM_INTERRUPTS, PLIC_NUM_PRIORITIES); | |
// Arty board PWM source is 65MHz. | |
// HiFive1 PWM source is 256MHz. | |
// Use 8-bit PWM0 to drive LED display. | |
PLIC_enable_interrupt(&g_plic, INT_PWM0_BASE); | |
PLIC_set_threshold(&g_plic, 0); | |
PLIC_set_priority(&g_plic, INT_PWM0_BASE, 1); | |
#ifdef ARTY | |
PWM0_REG(PWM_CFG) = PWM_CFG_STICKY | PWM_CFG_ZEROCMP | PWM_CFG_ENALWAYS | 6; | |
PWM0_REG(PWM_CMP0) = 80; | |
#else | |
PWM0_REG(PWM_CFG) = PWM_CFG_STICKY | PWM_CFG_ZEROCMP | PWM_CFG_ENALWAYS | 6; | |
PWM0_REG(PWM_CMP0) = 160; | |
#endif | |
PWM0_REG(PWM_CMP1) = 0xff; | |
PWM0_REG(PWM_CMP2) = 0xff; | |
PWM0_REG(PWM_CMP3) = 0xff; | |
// Use 16-bit PWM1 to get as close as we can to 1ms. | |
PLIC_enable_interrupt(&g_plic, INT_PWM1_BASE); | |
PLIC_set_threshold(&g_plic, 0); | |
PLIC_set_priority(&g_plic, INT_PWM1_BASE, 1); | |
#ifdef ARTY | |
PWM1_REG(PWM_CFG) = PWM_CFG_STICKY | PWM_CFG_ZEROCMP | PWM_CFG_ENALWAYS | 6; | |
PWM1_REG(PWM_CMP0) = 1016; | |
#else | |
PWM1_REG(PWM_CFG) = PWM_CFG_STICKY | PWM_CFG_ZEROCMP | PWM_CFG_ENALWAYS | 10; | |
PWM1_REG(PWM_CMP0) = 250; | |
#endif | |
PWM1_REG(PWM_CMP1) = 0xffff; | |
PWM1_REG(PWM_CMP2) = 0xffff; | |
PWM1_REG(PWM_CMP3) = 0xffff; | |
// Enable machine external interrupts. | |
set_csr(mie, MIP_MEIP); | |
// Enable interrupts in general. | |
set_csr(mstatus, MSTATUS_MIE); | |
} | |
static void vsync(void) | |
{ | |
vsync_status = 0; | |
while (!vsync_status) | |
; | |
} | |
int main() | |
{ | |
int state = 0; | |
time_ms = 0; | |
frame_buffer = buf0; | |
draw_buffer = buf1; | |
// This code assumes you've | |
// set up your PLL to run at 256MHz. | |
//setup_pll(); | |
setup_gpio(); | |
setup_timers(); | |
while (1) { | |
vsync(); | |
uint16_t *tmp = frame_buffer; | |
frame_buffer = draw_buffer; | |
draw_buffer = tmp; | |
// Code to actually fill in your frame_buffer | |
// would go here. | |
} | |
} |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This software is licensed under the Apache 2 license, quoted below. | |
Apache License | |
Version 2.0, January 2004 | |
http://www.apache.org/licenses/ | |
TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION | |
1. Definitions. | |
"License" shall mean the terms and conditions for use, reproduction, | |
and distribution as defined by Sections 1 through 9 of this document. | |
"Licensor" shall mean the copyright owner or entity authorized by | |
the copyright owner that is granting the License. | |
"Legal Entity" shall mean the union of the acting entity and all | |
other entities that control, are controlled by, or are under common | |
control with that entity. For the purposes of this definition, | |
"control" means (i) the power, direct or indirect, to cause the | |
direction or management of such entity, whether by contract or | |
otherwise, or (ii) ownership of fifty percent (50%) or more of the | |
outstanding shares, or (iii) beneficial ownership of such entity. | |
"You" (or "Your") shall mean an individual or Legal Entity | |
exercising permissions granted by this License. | |
"Source" form shall mean the preferred form for making modifications, | |
including but not limited to software source code, documentation | |
source, and configuration files. | |
"Object" form shall mean any form resulting from mechanical | |
transformation or translation of a Source form, including but | |
not limited to compiled object code, generated documentation, | |
and conversions to other media types. | |
"Work" shall mean the work of authorship, whether in Source or | |
Object form, made available under the License, as indicated by a | |
copyright notice that is included in or attached to the work | |
(an example is provided in the Appendix below). | |
"Derivative Works" shall mean any work, whether in Source or Object | |
form, that is based on (or derived from) the Work and for which the | |
editorial revisions, annotations, elaborations, or other modifications | |
represent, as a whole, an original work of authorship. For the purposes | |
of this License, Derivative Works shall not include works that remain | |
separable from, or merely link (or bind by name) to the interfaces of, | |
the Work and Derivative Works thereof. | |
"Contribution" shall mean any work of authorship, including | |
the original version of the Work and any modifications or additions | |
to that Work or Derivative Works thereof, that is intentionally | |
submitted to Licensor for inclusion in the Work by the copyright owner | |
or by an individual or Legal Entity authorized to submit on behalf of | |
the copyright owner. For the purposes of this definition, "submitted" | |
means any form of electronic, verbal, or written communication sent | |
to the Licensor or its representatives, including but not limited to | |
communication on electronic mailing lists, source code control systems, | |
and issue tracking systems that are managed by, or on behalf of, the | |
Licensor for the purpose of discussing and improving the Work, but | |
excluding communication that is conspicuously marked or otherwise | |
designated in writing by the copyright owner as "Not a Contribution." | |
"Contributor" shall mean Licensor and any individual or Legal Entity | |
on behalf of whom a Contribution has been received by Licensor and | |
subsequently incorporated within the Work. | |
2. Grant of Copyright License. Subject to the terms and conditions of | |
this License, each Contributor hereby grants to You a perpetual, | |
worldwide, non-exclusive, no-charge, royalty-free, irrevocable | |
copyright license to reproduce, prepare Derivative Works of, | |
publicly display, publicly perform, sublicense, and distribute the | |
Work and such Derivative Works in Source or Object form. | |
3. Grant of Patent License. Subject to the terms and conditions of | |
this License, each Contributor hereby grants to You a perpetual, | |
worldwide, non-exclusive, no-charge, royalty-free, irrevocable | |
(except as stated in this section) patent license to make, have made, | |
use, offer to sell, sell, import, and otherwise transfer the Work, | |
where such license applies only to those patent claims licensable | |
by such Contributor that are necessarily infringed by their | |
Contribution(s) alone or by combination of their Contribution(s) | |
with the Work to which such Contribution(s) was submitted. If You | |
institute patent litigation against any entity (including a | |
cross-claim or counterclaim in a lawsuit) alleging that the Work | |
or a Contribution incorporated within the Work constitutes direct | |
or contributory patent infringement, then any patent licenses | |
granted to You under this License for that Work shall terminate | |
as of the date such litigation is filed. | |
4. Redistribution. You may reproduce and distribute copies of the | |
Work or Derivative Works thereof in any medium, with or without | |
modifications, and in Source or Object form, provided that You | |
meet the following conditions: | |
(a) You must give any other recipients of the Work or | |
Derivative Works a copy of this License; and | |
(b) You must cause any modified files to carry prominent notices | |
stating that You changed the files; and | |
(c) You must retain, in the Source form of any Derivative Works | |
that You distribute, all copyright, patent, trademark, and | |
attribution notices from the Source form of the Work, | |
excluding those notices that do not pertain to any part of | |
the Derivative Works; and | |
(d) If the Work includes a "NOTICE" text file as part of its | |
distribution, then any Derivative Works that You distribute must | |
include a readable copy of the attribution notices contained | |
within such NOTICE file, excluding those notices that do not | |
pertain to any part of the Derivative Works, in at least one | |
of the following places: within a NOTICE text file distributed | |
as part of the Derivative Works; within the Source form or | |
documentation, if provided along with the Derivative Works; or, | |
within a display generated by the Derivative Works, if and | |
wherever such third-party notices normally appear. The contents | |
of the NOTICE file are for informational purposes only and | |
do not modify the License. You may add Your own attribution | |
notices within Derivative Works that You distribute, alongside | |
or as an addendum to the NOTICE text from the Work, provided | |
that such additional attribution notices cannot be construed | |
as modifying the License. | |
You may add Your own copyright statement to Your modifications and | |
may provide additional or different license terms and conditions | |
for use, reproduction, or distribution of Your modifications, or | |
for any such Derivative Works as a whole, provided Your use, | |
reproduction, and distribution of the Work otherwise complies with | |
the conditions stated in this License. | |
5. Submission of Contributions. Unless You explicitly state otherwise, | |
any Contribution intentionally submitted for inclusion in the Work | |
by You to the Licensor shall be under the terms and conditions of | |
this License, without any additional terms or conditions. | |
Notwithstanding the above, nothing herein shall supersede or modify | |
the terms of any separate license agreement you may have executed | |
with Licensor regarding such Contributions. | |
6. Trademarks. This License does not grant permission to use the trade | |
names, trademarks, service marks, or product names of the Licensor, | |
except as required for reasonable and customary use in describing the | |
origin of the Work and reproducing the content of the NOTICE file. | |
7. Disclaimer of Warranty. Unless required by applicable law or | |
agreed to in writing, Licensor provides the Work (and each | |
Contributor provides its Contributions) on an "AS IS" BASIS, | |
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or | |
implied, including, without limitation, any warranties or conditions | |
of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A | |
PARTICULAR PURPOSE. You are solely responsible for determining the | |
appropriateness of using or redistributing the Work and assume any | |
risks associated with Your exercise of permissions under this License. | |
8. Limitation of Liability. In no event and under no legal theory, | |
whether in tort (including negligence), contract, or otherwise, | |
unless required by applicable law (such as deliberate and grossly | |
negligent acts) or agreed to in writing, shall any Contributor be | |
liable to You for damages, including any direct, indirect, special, | |
incidental, or consequential damages of any character arising as a | |
result of this License or out of the use or inability to use the | |
Work (including but not limited to damages for loss of goodwill, | |
work stoppage, computer failure or malfunction, or any and all | |
other commercial damages or losses), even if such Contributor | |
has been advised of the possibility of such damages. | |
9. Accepting Warranty or Additional Liability. While redistributing | |
the Work or Derivative Works thereof, You may choose to offer, | |
and charge a fee for, acceptance of support, warranty, indemnity, | |
or other liability obligations and/or rights consistent with this | |
License. However, in accepting such obligations, You may act only | |
on Your own behalf and on Your sole responsibility, not on behalf | |
of any other Contributor, and only if You agree to indemnify, | |
defend, and hold each Contributor harmless for any liability | |
incurred by, or claims asserted against, such Contributor by reason | |
of your accepting any such warranty or additional liability. | |
END OF TERMS AND CONDITIONS | |
APPENDIX: How to apply the Apache License to your work. | |
To apply the Apache License to your work, attach the following | |
boilerplate notice, with the fields enclosed by brackets "[]" | |
replaced with your own identifying information. (Don't include | |
the brackets!) The text should be enclosed in the appropriate | |
comment syntax for the file format. We also recommend that a | |
file or class name and description of purpose be included on the | |
same "printed page" as the copyright notice for easier | |
identification within third-party archives. | |
Copyright 2016 SiFive, Inc. | |
Licensed under the Apache License, Version 2.0 (the "License"); | |
you may not use this file except in compliance with the License. | |
You may obtain a copy of the License at | |
http://www.apache.org/licenses/LICENSE-2.0 | |
Unless required by applicable law or agreed to in writing, software | |
distributed under the License is distributed on an "AS IS" BASIS, | |
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | |
See the License for the specific language governing permissions and | |
limitations under the License. |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment