| Start 0 1 2 3 4 5 6 7 P Stop
Request by host
-Start bit: can be long as 300-350us.
+Start bit: can be long as 300-350us during start up and upto 2500us while key scanning
Request: Host pulls Clock line down to request to send a command.
Timing: After Request keyboard pull up Data and down Clock line to low for start bit.
After request host release Clock line once Data line becomes hi.
clock_lo();
/* wait for Start bit(Clock:lo/Data:hi) */
- WAIT(data_hi, 300, 0x30);
+ WAIT(data_hi, 5000, 0x30);
/* Data bit */
for (uint8_t i = 0; i < 8; i++) {
return 0;
ERROR:
idle();
- if (ibm4704_error > 0x30) {
+ if (ibm4704_error >= 0x30) {
xprintf("S:%02X ", ibm4704_error);
}
IBM4704_INT_ON();