H8S2258 Datasheet, PDF (164/1071 Pages) Renesas Technology Corp – 16-Bit Single-Chip Microcomputer H8S Family/H8S/2200 Series

Section 2 CPU
2.5.2 Memory Data Formats
Figure 2.10 shows the data formats in memory. The H8S/2000 CPU can access word data and
longword data in memory, but word or longword data must begin at an even address. If an attempt
is made to access word or longword data at an odd address, no address error occurs but the least
significant bit of the address is regarded as 0, so the access starts at the preceding address. This
also applies to instruction fetches.
When ER7 is used as an address register to access the stack, the operand size should be word or
longword.
Data Type
1-bit data
Byte data
Address
Address L
Address L
Data Format
7
76
0
543210
MSB
LSB
Word data
Longword data
Address 2M
MSB
Address 2M + 1
Address 2N
MSB
Address 2N + 1
Address 2N + 2
Address 2N + 3
LSB
LSB
Figure 2.10 Memory Data Formats
Rev. 5.00 Aug 08, 2006 page 78 of 982
REJ09B0054-0500