Garnet-MM - Universal Driver Documentation

Digital I/O

GMM-24: 3 8-bit bidirectional ports (1 82C55 chip)
GMM-48: 6 8-bit bidirectional ports (2 82C55 chips)

Digital I/O ports on Garnet-MM require direction to be set with dscDIOSetConfig() before use. One configuration byte is required for each 82C55 chip.

All DIO lines power-up in input mode and have readback capability.

DIO lines on this board do not have pull-up resistors.

Interrupts

GMM-24: 1; source is digital I/O bit C0 of the 82C55 chip
GMM-48: 2; sources are digital I/O bit C0 of each 82C55 chip Interrupt levels are configured with jumpers.

Garnet-MM Universal Driver Functions

dscDIOSetBit()
dscDIOClearBit()
dscDIOInputBit()
dscDIOInputByte()
dscDIOOutputBit()
dscDIOOutputByte()
dscDIOSetConfig()
dscSetUserInterruptFunction()
dscClearUserInterruptFunction()
dscUserInt()