UPD780957 Datasheet, PDF (164/326 Pages) NEC – 8-Bit Single-Chip Microcontrollers

CHAPTER 9 8-BIT TIMERS 80 TO 83
9.1 Outline of 8-Bit Timers 80 to 83
These 8-bit timers can be used as interval timers.
9.2 Functions of 8-Bit Timers 80 to 83
8-bit timers 80 to 83 have an interval timer function. The interval timer generates an interrupt request repeatedly,
using the preset count value as interval.
8-bit timer 82 is used to control the external event clock input operation of 16-bit timer/event counter 2.
8-bit timer 83 is used for the real-time output function reload timing.
9.3 Configuration of 8-Bit Timers 80 to 83
8-bit timers 80 to 83 consist of the following hardware.
Item
Timer register
Register
Control register
Table 9-1. Configuration of 8-Bit Timers 80 to 83
Configuration
8-bit timer counter 8n (TM80, TM81, TM82, TM83)
8-bit compare register 8n (CR80, CR81, CR82, CR83)
8-bit timer control register 8n (TMC80, TMC81, TMC82, TMC83)
Remark n = 0 to 3
Figure 9-1 shows the block diagram of 8-bit timers 80 to 83.
Figure 9-1. Block Diagram of 8-Bit Timers 80 to 83
fXT1
fXT1/2
fXT1/2²
fCC
8-bit timer counter 8n
(TM8n)
Match
INTTM8n
3
8-bit compare register 8n
(CR8n)
TCE8n TCL8n1 TCL8n0
8-bit timer control register 8n
(TMC8n)
Internal bus
Caution The count clocks in the figure above are those of TM80 and TM81. For the count clocks of
TM82 and TM83, refer to Table 9-2.
Remark n = 0 to 3
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User’s Manual U13655EJ2V1UD