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Section 2 CPU
Rev. 6.00 Sep 12, 2006 page 22 of 526
REJ09B0326-0600
2.3.2
Memory Data Formats
Figure 2.4 indicates the data formats in memory. For access by the H8/300L CPU, word data
stored in memory must always begin at an even address. When word data beginning at an odd
address is accessed, the least significant bit is regarded as 0, and the word data beginning at the
preceding address is accessed. The same applies to instruction codes.
Data Format
7
6
5
4
3
2
1
0
Address
Data Type
7
0
Address n
MSB
LSB
MSB
LSB
Upper 8 bits
Lower 8 bits
MSB
LSB
CCR
CCR
*
MSB
LSB
MSB
LSB
Address n
Even address
Odd address
Even address
Odd address
Even address
Odd address
1-bit data
Byte data
Word data
Byte data (CCR) on stack
Word data on stack
Legend:
CCR:
Condition code register
Note:
*
Ignored on return
Figure 2.4 Memory Data Formats
When the stack is accessed using R7 as an address register, word access should always be
performed. The CCR is stored as word data with the same value in the upper 8 bits and the lower 8
bits. On return, the lower 8 bits are ignored.
Summary of Contents for F-ZTAT H8/3642A Series
Page 6: ...Rev 6 00 Sep 12 2006 page iv of xx ...
Page 8: ...Rev 6 00 Sep 12 2006 page vi of xx ...
Page 22: ...Rev 6 00 Sep 12 2006 page xx of xx ...
Page 124: ...Section 5 Power Down Modes Rev 6 00 Sep 12 2006 page 102 of 526 REJ09B0326 0600 ...
Page 188: ...Section 6 ROM Rev 6 00 Sep 12 2006 page 166 of 526 REJ09B0326 0600 ...
Page 190: ...Section 7 RAM Rev 6 00 Sep 12 2006 page 168 of 526 REJ09B0326 0600 ...
Page 298: ...Section 9 Timers Rev 6 00 Sep 12 2006 page 276 of 526 REJ09B0326 0600 ...
Page 378: ...Section 12 A D Converter Rev 6 00 Sep 12 2006 page 356 of 526 REJ09B0326 0600 ...
Page 446: ...Section 13 Electrical Characteristics Rev 6 00 Sep 12 2006 page 424 of 526 REJ09B0326 0600 ...