Renesas M32R-FPU - Manual (Page 22)

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1-14 M32R-FPU Software Manual (Rev.1.01)
(2) Data format in memory
The data sizes in memory can be byte (8 bits), halfword (16 bits) or word (32 bits).
Although byte data can be located at any address, halfword and word data must be
located at the addresses aligned with a halfword boundary (least significant
a d d r e s s b i t = " 0 " ) o r a w o r d b o u n d a r y ( t w o l o w - o r d e r a d d r e s s b i t s = " 0 0 " ) ,
respectively. If an attempt is made to access memory data that overlaps the
halfword or word boundary, an address exception occurs.
Address
byte
half
word
word
+0 address +1 address +2 address +3 address
b0 b31
byte
byte
byte
byte
halfword
halfword
word
7 8 15 16 23 24
Figure 1.6.3 Data Format in Memory
CPU PROGRAMMING MODEL
1.6 Data Format