ece3221lab5.c

void outchar(char ch) {
  volatile int* JTAG_UART = (int*) 0x00008840;
  *JTAG_UART = ch; // Write char to display.
}

char bin2hex(char hex) {
  hex &= 0x0F; // Mask last 4 bits.
  return hex <= 9 ? hex + '0' : hex - 10 + 'A';
}

void outhex(char n) {
  char msn = n >> 4; // put first 4 bits into msn (most significant nibble)
  outchar(bin2hex(msn));
  outchar(bin2hex(n));
}