p2125vps20 Renesas Electronics Corporation., p2125vps20 Datasheet - Page 96

• Manufacturer Part Number: p2125vps20
• Description: 16-bit Single-chip Microcomputer H8s Family / H8s/2100 Series
• Manufacturer: Renesas Electronics Corporation.

Section 3 MCU Operating Modes
3.2
The following registers are related to the operating modes. For details on the bus control register
(BCR), see section 6.3.1, Bus Control Register (BCR).
• Mode control register (MDCR)
• System control register (SYSCR)
• Serial timer control register (STCR)
3.2.1
MDCR is used to set an operating mode and to monitor the current operating mode.
Notes: 1. The initial value is determined by the MD2 pin. The MD2 pin is not supported in SDIP-
Rev. 1.00 Sep. 21, 2006 Page 58 of 658
REJ09B0310-0100
Bit
7
6 to 3 —
2
1
0
2. The initial value is determined by the MD1 and MD0 pins.
Bit Name
EXPE
MDS2
MDS1
MDS0
Register Descriptions
Mode Control Register (MDCR)
64 and QFP-64. This bit is always read as 0.
0
All 0
Initial
Value
—*
—*
—*
1
2
2
R/W
R/W
R
R
R
R
Extended Mode Enable
Description
Mode 1
This bit is fixed to 1 and cannot be modified.
Mode 2 and 3
0: Single-chip mode
1: On-chip ROM enabled extended mode
Reserved
The initial value should not be changed.
Mode Select 2 to 0
These bits indicate the input levels at mode pins (MD2, MD1,
and MD0) (the current operating mode). The MDS2, MDS1,
and MDS0 bits correspond to the MD2, MD1, and MD0 pins,
respectively. These bits are read-only bits and cannot be
written to.
The input levels of the mode pins (MD2, MD1, and MD0) are
latched into these bits when MDCR is read. These latches
are canceled by a reset.