HD6475328-CP10 HITACHI [Hitachi Semiconductor], HD6475328-CP10 Datasheet - Page 49

• Manufacturer Part Number: HD6475328-CP10
• Description: original Hitachi CMOS microcomputer unit (MCU)
• Manufacturer: HITACHI [Hitachi Semiconductor]

2.4 Mode Control Register (MDCR)
Another control register in the register field in page 0 is the mode control register (MDCR). The
inputs at the mode pins are latched in this register on the rising edge of the signal. The mode
control register can be read by the CPU, but not written. Table 3-2 lists the attributes of this
register.
Table 2-2 Mode Control Register
Name
Mode control register
The bit configuration of this register is shown below.
Bit
Initial value
Read/Write
* Initialized according to MD
Bits 7 and 6—Reserved: These bits cannot be modified and are always read as “1.”
Bits 5 to 3—Reserved: These bits cannot be modified and are always read as “0.”
Bits 2 to 0—Mode Select 2 to 0 (MDS2 to MDS0): These bits indicate the values of the mode
pins (MD
to MD
Coding Example: To test whether the MCU is operating in mode 1:
The comparison is with H'C1 instead of H'01 because bits 7 and 6 are always read as “1.”
1
, and MDS0 to MD
2
to MD
0
—
—
) latched on the rising edge of the signal. MDS2 corresponds to MD
7
1
0
. These bits can be read but not written.
Abbreviation
MDCR
—
—
6
1
CMP:G.B #H'C1, @H'FFFA
2
to MD
0
—
—
5
0
.
29
—
—
4
0
Read/Write
Read only
—
—
3
0
MDS2
Address
H'FFFA
R
2
*
MDS1
R
1
*
MDS0
2
, MDS1
R
0
*