Renesas R8C/20 User Manual

R8C/20 Group, R8C/21 Group 14. Timers
Rev.2.00 Aug 27, 2008 Page 185 of 458
REJ09B0250-0200
i = 0 or 1, j = either A, B, C or D
Table 14.25 Output Compare Function Specifications
Item Specification
Count Sources f1, f2, f4, f8, f32, fOCO40M
External signal input to the TRDCLK pin (valid edge selected by a program)
Count Operations Increment
Count Period • When the CCLR2 to CCLR0 bits in the TRDCRi register are set to 000b (free-
running operation)
1/fk × 65536 fk: Frequency of count source
• The CCLR1 to CCLR0 bits in the TRDCRi register are set to 01b or 10b (set the
TRDi register to 0000h at the compare match in the TRDGRji register.)
Frequency of count source x (n + 1)
n: Setting value in the TRDGRji register
Waveform Output Timing Compare match
Count Start Condition Write 1 (count starts) to the TSTARTi bit in the TRDSTR register.
Count Stop Conditions • Write 0 (count stops) to the TSTARTi bit in the TRDSTR register when the CSELi
bit in the TRDSTR register is set to 1.
The output compare output pin holds output level before the count stops.
• When the CSELi bit in the TRDSTR register is set to 0, the count stops at the
compare match in the TRDGRAi register.
The output compare output pin holds level after output change by the
compare match.
Interrupt Request Generation
Timing
• Compare match (the content in the TRDi register matches with the content in the
TRDGRji register.)
• TRDi register overflows
TRDIOA0 Pin Function Programmable I/O port, output-compare output or TRDCLK (external clock) input
TRDIOB0, TRDIOC0, TRDIOD0,
TRDIOA1 to TRDIOD1 Pin
Functions
Programmable I/O port or output-compare output (select every pin)
INT0
Pin Function Programmable I/O port, pulse output forced cutoff signal input or INT0 interrupt
input
Read from Timer The count value can be read by reading the TRDi register.
Write to Timer • When the SYNC bit in the TRDMR register is set to 0 (channels 0 and 1 operate
independently)
Data can be written to the TRDi register.
• When the SYNC bit in the TRDMR register is set to 1 (channels 0 and 1 operate
synchronously).
Data can be written to both the TRD0 and TRD1 registers by writing to the TRDi
register.
Selection Functions • Output-compare output pin selected
Either 1 pin or multiple pins of the TRDIOAi, TRDIOBi, TRDIOCi or TRDIODi pin.
• Output level at the compare match selected
“L” output, “H” output or output level inversed
• Initial output level selected
Set the level at period from the count start to the compare match.
• Timing to set the TRDi register to 0000h
Overflow or compare match in the TRDGRAi register
• Buffer operation (refer to
14.3.2 Buffer Operation)
• Synchronous operation (refer to
14.3.3 Synchronous Operation)
• Output pin in the TRDGRCi and TRDGRDi registers changed
The TRDGRCi register can be used as output control of the TRDIOAi pin and the
TRDGRDi register can be used as output control of the TRDIOBi pin.
• Pulse output forced cutoff signal input (refer to
14.3.4 Pulse Output Forced
Cutoff
)
• Timer RD can be used as the internal timer without output.

Renesas R8C/20 Specifications

General

Brand	Renesas
Model	R8C/20
Category	Control Unit
Language	English