Intel 386 - Manual (Page 247)

Intel386™ EX EMBEDDED PROCESSOR USER’S MANUAL
10-4
Table 10-2. TCU Associated Registers
Register
Expanded
Address
PC/AT*
Address
Function
P3CFG
PINCFG
(read/write)
0F824H
0F826H — Peripheral Pin Selections:
These registers determine whether a counter’s input and output
signals are connected to package pins.
TMRCFG
(read/write)
0F834H — Timer Configuration:
Enables the counter’s CLKIN n input signal, selects the CLKINn
connection (PSCLK or TMRCLK n) for each counter, and either
connects TMRGATE n or V
CC
to each counter’s GATE n input signal,
or sets GATE n high or low through register bits.
TMRCON 0F043H 0043H TMRCON has three formats: control word, counter-latch, and read-
back. When writing to TMRCON, certain bit settings determine which
format is accessed.
Control Word Format:
Programs a specific counter. Selects a counter’s operating mode and
count format. After programming a counter, you can write a count
value to the counter’s TMR
n register at any time.
Counter-latch Format:
Issues a counter-latch command to a specific counter. The counter-
latch command allows you to latch the count of a specified counter.
After issuing a counter-latch command, you can check the counter’s
count by reading the counter’s TMR
n register.
Read-back Format:
Issues a read-back command to one or more counters. The read-
back command allows you to latch the count and status of one or
more counters. After issuing the read-back command, you can check
the counter’s status by reading the counter’s TMR
n register. After
checking a counter’s status, you can read the counter’s TMR n
register again to check its count.
TMR0
TMR1
TMR2 0F040H
0F041H
0F042H 0040H
0041H
0042H Status Format:
Read this register after issuing a read-back command to check
counter
n’s status. Reading TMRn again accesses its read format.
Read Format:
Read this register to check counter
n’s count value.
Write Format:
Write this register at any time after initializing counter
n to change the
counter’s count value.