HD6433044 Datasheet, PDF (437/867 Pages) Hitachi Semiconductor – Hitachi Single-Chip Microcomputer

12.2.2 Timer Control/Status Register (TCSR)
TCSR is an 8-bit readable and writable^*1 register. Its functions include selecting the timer mode
and clock source.
Bit
Initial value
Read/Write
7
OVF
0
R/(W)^*2
6
WT/IT
0
R/W
5
TME
0
R/W
4
3
2
1
0
—
—
CKS2 CKS1 CKS0
1
1
0
0
0
—
—
R/W
R/W
R/W
Clock select
These bits select the
TCNT clock source
Reserved bits
Timer enable
Selects whether TCNT runs or halts
Timer mode select
Selects the mode
Overflow flag
Status flag indicating overflow
Bits 7 to 5 are initialized to 0 by a reset and in standby mode. Bits 2 to 0 are initialized to 0 by a
reset. In software standby mode bits 2 to 0 are not initialized, but retain their previous values.
Notes: 1. TCSR differs from other registers in being more difficult to write. For details see
section 12.2.4, Notes on Register Access.
2. Only 0 can be written, to clear the flag.
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