R8C/20 Group, R8C/21 Group 14. Timers
Rev.2.00 Aug 27, 2008 Page 214 of 458
REJ09B0250-0200
j = either A, B, C or D
Table 14.29 Reset Synchronous PWM Mode 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 The TRD0 register is incremented (The TRD1 register is not used.)
PWM Waveform PWM period: 1/fk × (m + 1)
Active level width of normal-phase:1/fk × (m - n)
Active level width of counter-phase:1/fk × (n + 1)
fk:Frequency of count source
m:Setting value in the TRDGRA0 register
n: Setting value in the TRDGRB0 register (PWM output 1),
Setting value in the TRDGRA1 register (PWM output 2),
Setting value in the TRDGRB1 register (PWM output 3)
Count Start Condition Write 1 (count starts) to the TSTART0 bit in the TRDSTR register.
Count Stop Conditions • Write 0 (count stops) to the TSTART0 bit in the TRDSTR register
when the CSEL0 bit in the TRDSTR register is set to 1.
• The PWM output pin holds output level before the count stops
• When the CSEL0 bit in the TRDSTR register is set to 0, the count
stops at the compare match in the TRDGRA0 register.
• The PWM output pin holds level after output change by the compare
match.
Interrupt Request Generation
Timing
• Compare match (the content in the TRD0 register matches with the
content in the TRDGRj0, TRDGRA1 and TRDGRB1 registers.)
• The TRD0 register overflows
TRDIOA0 Pin Function Programmable I/O port or TRDCLK (external clock) input
TRDIOB0 Pin Function PWM output 1 normal-phase output
TRDIOD0 Pin Function PWM output 1 counter-phase output
TRDIOA1 Pin Function PWM output 2 normal-phase output
TRDIOC1 Pin Function PWM output 2 counter-phase output
TRDIOB1 Pin Function PWM output 3 normal-phase output
TRDIOD1 Pin Function PWM output 3 counter-phase output
TRDIOC0 Pin Function Output inverted every period of PWM
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 TRD0 register.
Write to Timer The value can be written to the TRD0 register.
Selection Functions • The active level of normal-phase and counter-phase and initial
output level selected individually.
• Buffer operation (refer to 14.3.2 Buffer Operation.)
• Pulse output forced cutoff signal input (refer to 14.3.4 Pulse Output
Forced Cutoff.)
m + 1
Normal-phase
n + 1
(When “L” is selected for the active level)
Counter-phase
m - n
To Next Page
Loading...
Need help?
General
