Datasheet
Section 3 MCU Operating Modes
Rev. 2.00 Aug. 20, 2008 Page 64 of 1198
REJ09B0403-0200
3.2 Register Descriptions
The following registers are related to the operating mode. For details on the bus control register
(BCR), see section 6.3.1, Bus Control Register (BCR), and for details on bus control register 2
(BCR2), see section 6.3.2, Bus Control Register 2 (BCR2).
• Mode control register (MDCR)
• System control register (SYSCR)
• Serial timer control register (STCR)
3.2.1 Mode Control Register (MDCR)
MDCR is used to set an operating mode and to monitor the current operating mode.
Bit Bit Name
Initial
Value
R/W Description
7 EXPE 0 R/W Extended Mode Enable
Specifies extended mode.
0: Single-chip mode
1: Extended mode
6 to 3 All 0 R Reserved
2
1
MDS2
MDS1
*
*
R
R
Mode Select 2 and 1
These bits indicate the input levels at mode pins (MD2
and MD1) (the current operating mode). Bits MDS2 and
MDS1 correspond to MD2 and MD1, respectively. MDS2
and MDS1 are read-only bits and they cannot be written
to. The mode pin (MD2 and MD1) input levels are latched
into these bits when MDCR is read. These latches are
canceled by a reset.
0 R Reserved
Note: * The initial values are determined by the settings of the MD2 and MD1 pins.