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2 system control register (syscr) – Renesas H8S/2111B User Manual

Page 87

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Rev. 1.00, 05/04, page 53 of 544

3.2.2

System Control Register (SYSCR)

SYSCR selects a system pin function, monitors a reset source, selects the interrupt control mode
and the detection edge for NMI, pin location selection, enables or disables register access to the
on-chip peripheral modules, and enables or disables on-chip RAM address space.

Bit Bit

Name

Initial
Value R/W Description

7 and 6

All 0

R/W

Reserved

The initial value should not be changed.

5

4

INTM1

INTM0

0

0

R

R/W

These bits select the control mode of the interrupt
controller. For details on the interrupt control modes
and interrupt control select modes 1 and 0, see
section 5.6, Interrupt Control Modes and Interrupt
Operation.

00: Interrupt control mode 0

01: Interrupt control mode 1

10: Setting prohibited

11: Setting prohibited

3 XRST

1 R External

Reset

This bit indicates the reset source. A reset is caused
by an external reset input, or when the watchdog
timer overflows.

0: A reset is caused when the watchdog timer

overflows.

1: A reset is caused by an external reset.

2 NMIEG

0 R/W

NMI

Edge

Select

Selects the valid edge of the NMI interrupt input.

0: An interrupt is requested at the falling edge of NMI

input

1: An interrupt is requested at the rising edge of NMI

input

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