RX610 Group
17. 8-Bit Timer (TMR)
R01UH0032EJ0120 Rev.1.20
Page 566 of 1006
Feb 20, 2013
17.2.1
Timer Counter (TCNT)
Value after reset:
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
b4
b7
b0
b7
b3
b2
b1
b0
b6
b5
b4
b3
b2
b1
b6
b5
TMR0.TCNT (TMR2.TCNT)
TMR1.TCNT (TMR3.TCNT)
Addresses: TMR0.TCNT 0008 8208h, TMR1.TCNT 0008 8209h
TMR2.TCNT 0008 8218h, TMR3.TCNT 0008 8219h
TCNT is an 8-bit readable/writable up-counter.
TMR0.TCNT and TMR1.TCNT (TMR2.TCNT and TMR3.TCNT) comprise a single 16-bit counter so they can be
accessed together by a word transfer instruction.
The TCCR.CSS[1:0] and CKS[2:0] bits are used to select a clock.
TCNT can be cleared by an external reset input signal, compare match A signal, or compare match B signal. Which
signal to be used for clearing is selected by the TCR.CCLR[1:0] bits.
When TCNT overflows from FFh to 00h, the interrupt flag is set to 1.
For details on the corresponding interrupt vector number, see section 10, Interrupt Control Unit (ICU), and table 17.6,
TMR Interrupt Sources.
17.2.2
Time Constant Register A (TCORA)
Value after reset:
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
b4
b7
b0
b7
b3
b2
b1
b0
b6
b5
b4
b3
b2
b1
b6
b5
TMR0.TCORA (TMR2.TCORA)
TMR1.TCORA (TMR3.TCORA)
Addresses: TMR0.TCORA: 0008 8204h, TMR1.TCORA: 0008 8205h
TMR2.TCORA: 0008 8214h, TMR3.TCORA: 0008 8215h
TCORA is an 8-bit readable/writable register.
TMR0.TCORA and TMR1.TCORA (TMR2.TCORA and TMR3.TCORA) comprise a single 16-bit register so they can
be accessed together by a word transfer instruction.
The value in TCORA is continually compared with the value in TCNT. When a match is detected, the corresponding
compare match A signal is set to high. Note however that comparison is not performed during writing to TCORA. The
timer output from the TMOn pin can be freely controlled by this compare match A signal and the settings of the
TCSR.OSA[1:0] bits.