CNT24-4(PCI)
I/O Ports and Registers
37
Output Command
Count initial value
(Commands; CH0:00h, CH1:05h, CH2:0Ah, CH3:0Fh)
To set a count initial value, execute an OUT command for the
output port (+0) and set output port +1. The count data is 24 bit
data. Output the data eight times, eight bits at time. After the
last eight bits have been output, all data (24 bits) is loaded as the
count initial value.
The following sample program shows how to set the count initial
value 100 (64h) in CH0.
OUT 0h, 00h (CH0: Select count data)
OUT 1h, 64h (Lower bits)
OUT 1h, 00h (Middle bits)
OUT 1h, 00h (Upper bits)
Operation Mode
(Command CH0:01h, CH1:06h, CH2:0Bh, CH3:10h)
D7
D6
D5
D4
D3
D2
D1
D0
01h/06h/0Bh/10h
UD/AB
SEL
SEL2
SEL1
SEL0
DIR
RESET
ZSEL
Execute an OUT command for output port +0, then set an operation
mode on output port +1.
RESET Clears the 24 bit up-down counter to "00000h."
During RESET=0, counting is disabled.
0 : Clear counter
1 : Count