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Chapter 38 Reload Timer
1.Overview
Chapter 38 Reload Timer
1. Overview
The reload timer uses a 16 bit down counter to detect the input signal trigger and perform a count down.
The count length is 16 bits.
2. Features
Operation: 2 kinds of operation are possible
Format: 16 bit down counter with reload register
Quantity: 8 (Output: 8 channels TOT[0-7])
Clock mode: Select from two modes
• Internal clock mode
Count clock: CLKP/2, CLKP/8, CLKP/32, CLKP/64, CLKP/128
Activation triggers (4 types)
• External event clock mode
Count clock : External event (TIN[7:0] pins)
Count active edge: Rising/falling/both edges of external event
Activation trigger: Software trigger
Cycle : Cycle = count clock x (reload value + 1)
(Example) When count clock = 16MHz, reload value = 15999
Cycle = 62.5ns x (15999+1) = 1.0ms
Count active edge: When in external event mode, choose from 3 types.
• External trigger (rising /falling/both edges)
Interrupt: Request generated by underflow
Other 1: Counter stop in software/can be reopened
Other 2: Control of other peripheral functions possible
• PPG activation trigger source:
Reload timer 0 : PPG0, PPG1
Reload timer 1 : PPG2, PPG3
or
PPG
A/D
Reload value
Down counter
Pin
Latch
Output value
Reversal
Underflow
Reload
Internal clock
or
External event
To PPG
To A/D
Soft trigger
External event
• One-shot Operation
Initial output level
Reversed output level
• Reload Operation
Initial output level
Reversed output level
