HD6433308 Datasheet, PDF (49/349 Pages) Hitachi Semiconductor – Hitachi Single-Chip MicroComputer

3.4.2 Memory Data Formats
Figure 3-4 indicates the data formats in memory.
Word data stored in memory must always begin at an even address. In word access the least
significant bit of the address is regarded as “0.” If an odd address is specified, no address error
occurs but the access is performed at the preceding even address. This rule affects MOV.W
instructions and branching instructions, and implies that only even addresses should be stored in the
vector table.
Data type
Address
Data format
1-Bit data
Byte data
Word data
Byte data (CCR) on stack
Word data on stack
Address n
Address n
Even address
Odd address
Even address
Odd address
Even address
Odd address
7
0
765 43210
M
L
S
S
B
B
M
S _{Upper 8 bits}
B
L
Lower 8 bits S
B
M
L
S
CCR
S
B
B
M
L
S
CCR* ^S
B
B
M
S
B
L
S
B
CCR: Condition Code Register
*: Ignored when return
Figure 3-4. Memory Data Formats
The stack must always be accessed a word at a time. When the CCR is pushed on the stack, two
identical copies of the CCR are pushed to make a complete word. When they are returned, the
lower byte is ignored.
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