HD64F7050 RENESAS [Renesas Technology Corp], HD64F7050 Datasheet - Page 44

• Manufacturer Part Number: HD64F7050
• Description: 32-Bit RISC Microcomputer SuperH RISC engine Family/
• Manufacturer: RENESAS [Renesas Technology Corp]

Section 2 CPU
2.2
2.2.1
Register operands are always longwords (32 bits). When the memory operand is only a byte (8
bits) or a word (16 bits), it is sign-extended into a longword when loaded into a register (figure
2.4).
2.2.2
Memory data formats are classified into bytes, words, and longwords. Byte data can be accessed
from any address, but an address error will occur if you try to access word data starting from an
address other than 2n or longword data starting from an address other than 4n. In such cases, the
data accessed cannot be guaranteed. The hardware stack area, referred to by the hardware stack
pointer (SP, R15), uses only longword data starting from address 4n because this area holds the
program counter and status register (figure 2.5).
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Data Formats
Data Format in Registers
Data Format in Memory
Address 2n
Address 4n
31
Figure 2.4 Data Format in Registers
Figure 2.5 Data Format in Memory
Address m
31
Byte
Address m + 1
Word
Longword
23
Byte
Longword
Address m + 2
15
Byte
Address m + 3
Word
7
Byte
0
0