HD6433044 Datasheet, PDF (436/867 Pages) Hitachi Semiconductor – Hitachi 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
0
0
0
0
0
0
0
0
Read/Write
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
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.
Note: * TCNT is write-protected by a password. For details see section 12.2.4, Notes on Register
Access.
424