7 8-bit timers (tmra) – Toshiba H1 SERIES TLCS-900 User Manual

Page 101

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TMP92CM22

2007-02-16

92CM22-99

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

Table 3.7.1 Registers and Pins for Each Module

Module

Specification

Timer A01

Timer A23

Input pin for external clock

TA0IN

(Shared with PC0)

None

External pin

Output pin for timer
flip-flop

TA1OUT

(Shared with PC1)

TA3OUT

(Shared with PC5)

Timer RUN register

TA01RUN (1100H)

TA23RUN (1108H)

Timer register

TA0REG (1102H)
TA1REG (1103H)

TA2REG (110AH)
TA3REG (110BH)

Timer mode register

TA01MOD

(1104H)

TA23MOD

(110CH)

SFR
(Address)

Timer flip-flop control
register

TA1FFCR

(1105H)

TA3FFCR

(110DH)


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