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The key to programming the PCL-818L is to understand the function
of the card's 16 registers. The PCL-818L requires 16 consecutive
addresses in the PC's I/O space. Each address corresponds to a card
register. The address of each register is specified as an offset from the
card's base address. For example, BASE+0 is the card's base address
and BASE+7 is the base address + seven bytes. If the card's base
address is 300h, the register's address is 307h. The following sections
give detailed information on the layout and function of each of the
card's registers.
The following table shows the function of each register or driver and
its address relative to the card's base address.
Address
BASE+0
BASE+1
BASE+2
BASE+3
BASE+4
BASE+5
BASE+6
BASE+7
BASE+8
BASE+9
BASE+10
BASE+11
BASE+12
BASE+13
BASE+14
BASE+15
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PCL-818L User's Manual
Read
A/D low byte & channel
A/D high byte
MUX scan channel
D/I low byte (DI0-7)
N/A
N/A
N/A
N/A
Status
Control
N/A
D/I high byte (DI8-15)
Counter 0
Counter 1
Counter 2
N/A
Write
Software A/D trigger
A/D range control
MUX scan channel & range
control pointer
D/O low byte (DO0-7)
D/A 0 low byte
D/A 0 high byte
N/A
N/A
Clear interrupt request
Control
Counter enable
D/O high byte (DO8-15)
Counter 0
Counter 1
Counter 2
Counter control
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