Simple BCD coder

BcdCoderTests.java

public class BcdCoderTests extends InstrumentationTestCase {

    private int[][] decimalAndBcd = new int[][]{
            {0, 0},
            {1, 1},
            {2, 2},
            {3, 3},
            {4, 4},
            {5, 5},
            {6, 6},
            {7, 7},
            {8, 8},
            {9, 9},
            {16, 10},
            {17, 11},
            {18, 12},
            {19, 13},
            {20, 14},
            {21, 15},
            {22, 16},
            {23, 17},
            {24, 18},
            {25, 19},
            {32, 20},
            {33, 21},
            {34, 22},
            {35, 23},
            {36, 24},
            {37, 25},
            {38, 26},
            {39, 27},
            {40, 28},
            {41, 29},
            {48, 30},
            {49, 31}
    };

    public void testDecode() {

        for (int[] pair : this.decimalAndBcd) {

            int bcd = pair[0];
            int decimal = pair[1];

            Assert.assertEquals(decimal, SingleByteBcdCoder.decode((byte) bcd));

        }
    }

    public void testEncode() {

        for (int[] pair : this.decimalAndBcd) {

            int bcd = pair[0];
            int decimal = pair[1];

            Assert.assertEquals(bcd, SingleByteBcdCoder.encode(decimal));

        }
    }
}

SingleByteBcdCoder.java

public class SingleByteBcdCoder {

    public static byte encode(int i) {

        int tens = i / 10;
        int units = i - tens * 10;

        return (byte) (tens << 4 | units);
    }

    public static int decode(byte b) {

        int tens = b & 0xf0;
        tens = tens >> 4;
        int units = b & 0x0f;

        return tens * 10 + units;
    }
}