Square-Wave Output (8-Bit Resolution) Operation - NEC mPD780065 Series Preliminary User's Manual

7.4.3. Square-wave output (8-bit resolution) operation

A square wave with any selected frequency is output at intervals of the value preset to the 8-bit compare register
5n (CR5n).
TO5n pin output status is reversed at intervals of the count value preset to CR5n by setting bit 0 (TOE5n) of 8-
bit timer mode control register 5n (TMC5n) to 1. This enables a square wave with any selected frequency to be output
(duty = 50%).
[Setting]
<1> Set each register
• Set port latch and port mode register to 0.
• TCL5n: Select count clock
• CR5n: Compared value
• TMC5n: Clear and Start mode by match of TM5n and CR5n
<2> After TCE5n = 1 is set, count operation starts
<3> Timer output F/F is reversed by match of TM5n and CR5n. After INTTM5n is generated, TM5n is cleared
to 00H
<4> Timer output F/F is reversed at the same interval and square wave is output from TO5n
Remark n = 0,1
Count clock
TMn count value 00H
Count start
CR5n
Note
TO5n
Note TO5n output initial value can be set by bits 2 and 3 (LVR5n, LVS5n) of the 8-bit timer mode control register
5n (TMC5n)
Remark n = 0,1
CHAPTER 7 8-BIT TIMER/EVENT COUNTER
LVS5n LVR5n Timer output F/F status setting
1 0 High-level output
0 1 Low-level output
Timer output F/F reverse enable
Timer output enable → TOE5n = 1
Figure 7-9. Square-Wave Output Operation Timing
01H 02H N–1
N
Preliminary User's Manual U13420EJ2V0UM00
N 00H 01H 02H N–1 N 00H
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