HD64F3664FPV Datasheet, PDF (53/446 Pages) Renesas Technology Corp – Old Company Name in Catalogs and Other Documents

Section 2 CPU
2.3.2 Memory Data Formats
Figure 2.6 shows the data formats in memory. The H8/300H CPU can access word data and
longword data in memory, however 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, an address error does not
occur, however the least significant bit of the address is regarded as 0, so access begins the
preceding address. This also applies to instruction fetches.
When ER7 (SP) 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
Data Format
Address L
7
0
76 543210
Address L
MSB
LSB
Word data
Address 2M MSB
Address 2M+1
LSB
Longword data
Address 2N _MSB
Address 2N+1
Address 2N+2
Address 2N+3
LSB
Figure 2.6 Memory Data Formats
Rev. 6.00 Mar. 24, 2006 Page 23 of 412
REJ09B0142-0600