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3.7
8-Bit Timers (TMRA)
The TMP92CM22 features 4 built-in 8-bit timers.
These timers are paired into four modules: TMRA01 and TMRA23. Each module consists of two
channels and can operate in any of the following four operating modes.
•
8-bit interval timer mode
•
16-bit interval timer mode
•
8-bit programmable square wave pulse generation output mode (PPG: Variable duty
cycle with variable period)
•
8-bit pulse width modulation output mode (PWM: Variable duty cycle with constant
period)
Figure 3.7.1 and Figure 3.7.2 show block diagrams for TMRA01 and TMRA23.
Each channel consists of an 8-bit up counter, an 8-bit comparator and an 8-bit timer register.
In addition, a timer flip-flop and a prescaler are provided for each pair of channels.
The operation mode and timer flip-flops are controlled by five controls SFR (Special-function
registers).
Each of the two modules (TMRA01 and TMRA23) can be operated independently. All
modules operate in the same manner; hence only the operation of TMRA01 is explained here.
The contents of this chapter are as follows.
3.7.1 Block diagrams
3.7.2 Operation of Each Circuit
3.7.3 SFRs
3.7.4 Operation in Each Mode
(1) 8-bit timer mode
(2) 16-bit timer mode
(3) 8-bit PPG (Programmable pulse generation) output mode
(4) 8-bit PWM (Pulse width modulation) output mode
(5) Mode settings
Specification
External pin
SFR
(Address)
Table 3.7.1 Registers and Pins for Each Module
Module
Input pin for external clock
Output pin for timer
flip-flop
Timer RUN register
Timer register
Timer mode register
Timer flip-flop control
register
92CM22-99
Timer A01
Timer A23
TA0IN
None
(Shared with PC0)
TA1OUT
TA3OUT
(Shared with PC1)
(Shared with PC5)
TA01RUN (1100H)
TA23RUN (1108H)
TA2REG (110AH)
TA0REG (1102H)
TA1REG (1103H)
TA3REG (110BH)
TA01MOD
TA23MOD
(1104H)
(110CH)
TA1FFCR
TA3FFCR
(1105H)
(110DH)
TMP92CM22
2007-02-16
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