r4f2456 Renesas Electronics Corporation., r4f2456 Datasheet - Page 111

• Manufacturer Part Number: r4f2456
• Description: 16-bit Single-chip Microcomputer H8s Family / H8s/2400 Series
• Manufacturer: Renesas Electronics Corporation.

3.2.2
SYSCR selects saturation operation for the MAC instruction, controls CPU access to the flash
memory control registers, sets the external bus mode, and enables or disables on-chip RAM.
Bit
7, 6
5
4
3
2
Bit Name

MACS

FLSHE

System Control Register (SYSCR)
Initial Value
All 1
0
0
0
0
R/W
R/W
R/W
R/W
R/W

Descriptions
Reserved
The initial value should not be modified.
MAC Saturation Operation Control
Selects either saturation operation or non-saturation
operation for the MAC instruction.
0: MAC instruction performs non-saturation operation
1: MAC instruction performs saturation operation
Reserved
The initial value should not be modified.
Flash Memory Control Register Enable
Controls CPU access to the flash memory control
registers (FLMCR1, DFPR, and FLMSTR). If this bit
is set to 1, the flash memory control registers can be
read from and written to. If this bit is cleared to 0, the
flash memory control registers are not selected. At
this time, the contents of the flash memory control
registers are retained. 0 should be written to this bit in
LSIs other than the flash memory version.
0: Flash memory control registers are not selected for
1: Flash memory control registers are selected for
Reserved
This bit is always read as 0 and cannot be modified.
addresses H'FFFEB0 to H'FFFEB3
addresses H'FFFEB0 to H'FFFEB3
Rev. 1.00 Sep. 19, 2008 Page 81 of 1342
Section 3 MCU Operating Modes
REJ09B0467-0100