MB89630R Series
23
The RP indicates the address of the register bank currently in use. The relationship between the pointer contents
and the actual address is based on the conversion rule illustrated below.
The CCR consists of bits indicating the results of arithmetic operations and the contents of transfer data and
bits for control of CPU operations at the time of an interrupt.
H-flag:
Set to ‘1’ when a carry or a borrow from bit 3 to bit 4 occurs as a result of an arithmetic operation.
Cleared to ‘0’ otherwise. This flag is for decimal adjustment instructions.
I-flag:
Interrupt is enabled when this flag is set to ‘1’. Interrupt is disabled when the flag is cleared to ‘0’. Cleared
to ‘0’ at the reset.
IL1, IL0: Indicates the level of the interrupt currently allowed. Processes an interrupt only if its request level is
higher than the value indicated by this bit.
N-flag:
Set to ‘1’ if the MSB becomes to ‘1’ as the result of an arithmetic operation. Cleared to ‘0’ when the bit
is cleared to ‘0’.
Z-flag:
Set to ‘1’ when an arithmetic operation results in 0. Cleared to ‘0’ otherwise.
V-flag:
Set to ‘1’ if the complement on 2 overflows as a result of an arithmetic operation. Cleared to ‘0’ if the
overflow doesnot occur.
C-flag:
Set to ‘1’ when a carry or a borrow from bit 7 occurs as a result of an arithmetic operation. Cleared to ‘0’
otherwise.
Set to the shift-out value in the case of a shift instruction.
IL1
IL0
Interrupt level
High-low
0
0
1
High
Low
0
1
1
0
2
1
1
3
Rule for conversion of actual addresses of the general-purpose register area
“0”
↓
A15
“0”
↓
A14
“0”
↓
A13
“0”
↓
A12
“0”
↓
A11
“0”
↓
A10
“0”
↓
A9
“1”
↓
A8
R4
↓
A7
R3
↓
A6
R2
↓
A5
R1
↓
A4
R0
↓
A3
b2
↓
A2
b1
↓
A1
b0
↓
A0
Lower OP codes
RP
Generated addresses