TIMER TM-232

The interface TM-232 is an element of the measurement system KSP2. It works as a programmable timer.

Elements of the timer:

-	32-bit binary counter

-	clock quartz generator 10 MHz

-	divider f/100 of the clock frequency

-	address decoder

-	start/stop selector

Programming

Address	Write	Read
Base + 0	0..255: Stop counter	Counter: bits 0-7
Base + 1	0..255: Start counter	Counter: bits 8-15
Base + 2	0..255: Reset counter	Counter: bits 16-23
Base + 3	Not used	Counter: bits 24-31

Address Base + 0 should be read as the first. Reading of this address causes writing of the counter to the output register. Low significant bit (LSB) of the counter has value 10 μs.

Interface address:

Base address of the interface is selected by 6-stage binary selector. Sections 1..6 set  the address lines A7..A2. State ON = 0 and state OFF = 1. Typical address of the timer 132dec ($84). Binary selector: 1: OFF, 2: ON, 3: ON, 4: ON, 5: ON, 6: OFF.