3069RF-ZTAT Datasheet, PDF (463/1003 Pages) Renesas Technology Corp – RENESAS 16-BIT SINGLE-CHIP MICROCOMPUTER

12.2 Register Descriptions
12.2.1 Timer Counter (TCNT)
TCNT is an 8-bit readable and writable up-counter.
Bit
7
6
5
4
3
2
1
0
Initial value
Read/Write
0
R/W
0
0
0
0
0
0
0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Note: TCNT is write-protected by a password. For details see section 12.2.4, Notes on Register
Access.
When the TME bit is set to 1 in TCSR, TCNT starts counting pulses generated from an internal
clock source selected by bits CKS2 to CKS0 in TCSR. When the count overflows (changes from
H'FF to H'00), the OVF bit is set to 1 in TCSR. TCNT is initialized to H'00 by a reset and when
the TME bit is cleared to 0.
Rev. 5.0, 09/04, page 441 of 978