HD6433935 Hitachi, HD6433935 Datasheet - Page 197

• Manufacturer Part Number: HD6433935
• Description: 8-Bit MICROCONTROLLER
• Manufacturer: Hitachi

2. Timer counter A (TCA)
TCA is an 8-bit read-only up-counter, which is incremented by internal clock input. The clock
source for input to this counter is selected by bits TMA3 to TMA0 in timer mode register A
(TMA). TCA values can be read by the CPU in active mode, but cannot be read in subactive
mode. When TCA overflows, the IRRTA bit in interrupt request register 1 (IRR1) is set to 1.
TCA is cleared by setting bits TMA3 and TMA2 of TMA to 11.
Upon reset, TCA is initialized to H'00.
3. Clock stop register 1 (CKSTPR1)
Bit
Initial value
Read/Write
CKSTPR1 is an 8-bit read/write register that performs module standby mode control for peripheral
modules. Only the bit relating to timer A is described here. For details of the other bits, see the
sections on the relevant modules.
Bit 0: Timer A module standby mode control (TACKSTP)
Bit 0 controls setting and clearing of module standby mode for timer A.
TACKSTP
0
1
Bit
Initial value
Read/Write
Description
Timer A is set to module standby mode
Timer A module standby mode is cleared
S1CKSTP S31CKSTP S32CKSTP ADCKSTP TGCKSTP TFCKSTP TCCKSTP TACKSTP
R/W
7
1
TCA7
R
7
0
R/W
6
1
TCA6
R
6
0
R/W
TCA5
5
1
R
5
0
R/W
TCA4
4
1
R
4
0
TCA3
R/W
3
1
R
3
0
TCA2
R/W
R
2
0
2
1
TCA1
R/W
R
1
0
1
1
(initial value)
TCA0
R/W
R
0
0
0
1
185