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3.10) DIO – Digital I/O Register (offset 20, read / write)
This register is used to read and write to the digital I/O lines available on the External
Digital I/O Connector. Any compatible TTL Voltage can be fed into the digital input lines
(DI0-DI15) and read back using this register. When this register is written to, the voltages
on the Digital Output line will reflect the bit settings. The digital outputs are open
collector and can source 20mA.
DIO Register (read mode)
Bit 15 Bit 14 Bit 13 Bit 12 Bit 11 Bit 10 Bit 9 Bit 8
DI15 DI14 DI13 DI12 DI11 DI10 DI9 DI8
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
DI7 DI6
DI5 DI4 DI3 DI2 DI1 DI0
Bits 0-7: DI0 to DI7 - These bits are available on the digital I/O connector on the PC62C
Board. Any TTL compatible voltage can be fed into these lines and read back to
determine it status. If the voltage on the digital I/O connector is less than 0.6V
then a logical 0 will be read back. If the voltage is > 2V but less than 5.1V then a
logical 1 will be read back.
Bits 8-15: DI8 to DI15 - These bits are available on the digital I/O connector on the PC62C
Board. Any TTL compatible voltage can be fed into these lines and read back to
determine it status. If the voltage on the digital I/O connector is less than 0.6V
then a logical 0 will be read back. If the voltage is > 2V but less than 5.1V then a
logical 1 will be read back.
DIO Register (write mode)
Bit 15 Bit 14 Bit 13 Bit 12 Bit 11 Bit 10 Bit 9 Bit 8
DO15 DO14 DO13 DO12 DO11 DO10 DO9 DO8
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
DO7 DO6 DO5 DO4 DO3 DO2 DO1 DO0
Bits 0-7: DO0 to DO7 – These 8 bits are available on the digital I/O connector on the
PC62C Board. When this register is written to, the voltages on the low order
Digital Output lines (D0 – D7) will reflect the appropriate bit settings. The digital
outputs are TTL Compatible with open collector outputs and can source 20mA.
Bits 8-15: DO8 to DO15 - These 8 bits are available on the digital I/O connector on the
PC62C Board. When this register is written to, the voltages on the high byte
Digital Output lines (D8 – D15) will reflect the appropriate bit settings. The
digital outputs are TTL Compatible with open collector outputs and can source
20mA.
