h8s-2138 Renesas Electronics Corporation., h8s-2138 Datasheet - Page 429

• Manufacturer Part Number: h8s-2138
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2100 Series
• Manufacturer: Renesas Electronics Corporation.

14.2
14.2.1
TCNT is an 8-bit readable/writable * up-counter.
When the TME bit is set to 1 in TCSR, TCNT starts counting pulses generated from the internal
clock source selected by bits CKS2 to CKS0 in TCSR. When the TCNT value overflows (changes
from H'FF to H'00), the OVF flag in TCSR is set to 1, and an internal reset, NMI interrupt,
interval timer interrupt (WOVI), etc., can be generated, according to the mode selected by the
WT/IT bit and RST/NMI bit.
TCNT is initialized to H'00 by a reset, in hardware standby mode, or when the TME bit is cleared
to 0. It is not initialized in software standby mode.
Note: * TCNT is write-protected by a password to prevent accidental overwriting. For details
Bit
Initial value
Read/Write
Register Descriptions
Timer Counter (TCNT)
see section 14.2.4, Notes on Register Access.
R/W
7
0
R/W
6
0
R/W
5
0
R/W
4
0
Rev. 4.00 Jun 06, 2006 page 375 of 1004
R/W
3
0
Section 14 Watchdog Timer (WDT)
R/W
2
0
R/W
REJ09B0301-0400
1
0
R/W
0
0