Datasheet

Section 3 MCU Operating Modes
Page 86 of 1408 R01UH0309EJ0500 Rev. 5.00
Sep 24, 2012
H8S/2456, H8S/2456R, H8S/2454 Group
Bit Bit Name Initial Value R/W Descriptions
1 EXPE ⎯ R/W External Bus Mode Enable
Sets the external bus mode. In modes 1, 2, and 4,
this bit is fixed at 1 and cannot be modified. In modes
3 and 7, this bit can be read from and written to.
Writing 0 to this bit when its value is 1 should only be
carried out when an external bus cycle is not being
executed.
0: External address space is disabled
1: External address space is enabled
0 RAME 1 R/W RAM Enable
Enables or disables the on-chip RAM. This bit is
initialized when the reset state is canceled.
0: On-chip RAM is disabled
1: On-chip RAM is enabled