Input/Output Pins; Register Descriptions; Timer Counter (Tcnt); Table 15.1 Pin Configuration - Renesas H8S/2158 User Manual

15.2

Input/Output Pins

The WDT has the pins listed in table 15.1.

Table 15.1 Pin Configuration

Name
Reset output pin
External sub-clock
input pin
15.3

Register Descriptions

The WDT has the following registers. To prevent accidental overwriting, TCSR and TCNT have
to be written to in a method different from normal registers. For details, see section 15.6.1, Notes
on Register Access. For details on the system control register, see section 3.2.2, System Control
Register (SYSCR).
• Timer counter_0 (TCNT_0)
• Timer control/status register_0 (TCSR_0)
• Timer counter_1 (TCNT_1)
• Timer control/status register_1 (TCSR_1)
15.3.1

Timer Counter (TCNT)

TCNT is an 8-bit readable/writable up-counter.
TCNT is initialized to H'00 when the TME bit in timer control/status register (TCSR) is cleared to
0.
Symbol I/O
RESO
Output
EXCL Input
Section 15 Watchdog Timer (WDT)
Function
Outputs the counter overflow signal in
watchdog timer mode
Inputs the clock pulses to the WDT_1
prescaler counter
Rev. 3.00 Jan 25, 2006 page 375 of 872
REJ09B0286-0300