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 CLKIN
n
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 TMR
n
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.
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