h8s-2635 Renesas Electronics Corporation., h8s-2635 Datasheet - Page 141

• Manufacturer Part Number: h8s-2635
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2600 Series
• Manufacturer: Renesas Electronics Corporation.

Bit 7—Reserved: Only 1 should be written to these bits.
Bits 6 to 3—Reserved: These bits are always read as 0 and cannot be modified.
Bits 2 to 0—Mode Select 2 to 0 (MDS2 to MDS0): These bits indicate the input levels at pins
MD2 to MD0 (the current operating mode). Bits MDS2 to MDS0 correspond to MD2 to MD0.
MDS2 to MDS0 are read-only bits, and they cannot be written to. The mode pin (MD2 to MD0)
input levels are latched into these bits when MDCR is read. These latches are cancelled by a reset.
3.2.2
SYSCR is an 8-bit readable-writable register that selects saturating or non-saturating calculation
for the MAC instruction, selects the interrupt control mode, selects the detected edge for NMI, and
enables or disenables on-chip RAM.
SYSCR is initialized to H'01 by a reset and in hardware standby mode. SYSCR is not initialized in
software standby mode.
Bit 7—MAC Saturation (MACS): Selects either saturating or non-saturating calculation for the
MAC instruction.
Bit 6—Reserved: This bit is always read as 0 and cannot be modified.
Bit 7
MACS
0
1
Bit
Initial value
R/W
System Control Register (SYSCR)
Description
Non-saturating calculation for MAC instruction
Saturating calculation for MAC instruction
:
:
:
MACS
R/W
7
0


6
0
INTM1
R/W
5
0
INTM0
R/W
4
0
Rev. 6.00 Feb 22, 2005 page 81 of 1484
NMIEG
R/W
3
0
Section 3 MCU Operating Modes


2
0
REJ09B0103-0600


1
0
(Initial value)
RAME
R/W
0
1