HD6413308 Hitachi Semiconductor, HD6413308 Datasheet - Page 49

• Manufacturer Part Number: HD6413308
• Description: Hitachi Single-Chip MicroComputer
• Manufacturer: Hitachi Semiconductor

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.
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.
1-Bit data
Byte data
Word data
Byte data (CCR) on stack
Word data on stack
Data type
Figure 3-4. Memory Data Formats
CCR: Condition Code Register
*
: Ignored when return
Address
Address n
Address n
Even address
Even address
Even address
Odd address
Odd address
Odd address
33
7 6 5 4 3 2 1 0
7
M
S
B
M
S
B
M
S
B
M
S
B
M
S
B
Data format
Upper 8 bits
Lower 8 bits
CCR
CCR
*
0
L
S
B
L
S
B
L
S
B
L
S
B
L
S
B