
MULTI-MODE COUNTER CHAPTER 14
14-6
Signal levels are all TTL logic (0 to 5V).
The following signals at J10 are used to measur e pulse
widths:
J10 pin Description
4 Counter gate. Measures when low.
7 4.608 M HZ clock output. Tie to J10-9
9 Clock input. Tie to J10-7
The LS7166 ICR register is program med so input A
(J10-9) is up count input and GATE input (J10-9) acts to
enable inputs A/B when low.
If desired, LOAD input (J10-6) can be used to reset the
counter. If this is de sired, make su re the O L register is
programmed for 0.
See the demonstration program CNTR6.BAS for a
working example.
Basic operation is a follows:
Set the counter to 0
Read the counter and wait until it stops changing
after it starts
Read the counter
Multiply result by 2.170139E-7
The result is the actual time.
J10 Pin out
The following is the pin out for J10.
J10
pin
Function
1 Ground
2 4.608 M HZ clock output
3 Sound output
4 Gate input
5 +5V
6 Load counter
7 INT 1 input
8 B counter input
9 A counter input
10 High voltage input
COMMANDS
The following commands are used with the multi-mode
counter.
Command Function
COU NT(8) Reads multi-mode counter
ON ITR 1 Interrupt tasking
INP I/O port read
OUT Write to I/O port
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