H8S-2350 RENESAS [Renesas Technology Corp], H8S-2350 Datasheet - Page 123

• Manufacturer Part Number: H8S-2350
• Description: 16-Bit Single-Chip Microcomputer
• Manufacturer: RENESAS [Renesas Technology Corp]

4.7
When accessing word data or longword data, the H8S/2350 Group assumes that the lowest address
bit is 0. The stack should always be accessed by word transfer instruction or longword transfer
instruction, and the value of the stack pointer (SP, ER7) should always be kept even. Use the
following instructions to save registers:
Use the following instructions to restore registers:
Setting SP to an odd value may lead to a malfunction. Figure 4.6 shows an example of what
happens when the SP value is odd.
Legend:
Note: This diagram illustrates an example in which the interrupt control mode is 0,
PUSH.W
PUSH.L
POP.W
POP.L
SP
Notes on Use of the Stack
SP set to H'FFFEFF
in advanced mode.
CCR: Condition code register
PC:
R1L: General register R1L
SP:
TRAPA instruction executed
Rn
ERn
Rn
ERn
Stack pointer
Program counter
Figure 4.6 Operation when SP Value is Odd
(or MOV.W Rn, @-SP)
(or MOV.L ERn, @-SP)
(or MOV.W @SP+, Rn)
(or MOV.L @SP+, ERn)
SP
Data saved above SP
CCR
PC
MOV.B R1L, @–ER7
SP
Rev. 3.00 Sep 15, 2006 page 89 of 988
Contents of CCR lost
Section 4 Exception Handling
R1L
PC
REJ09B0330-0300
H'FFFEFA
H'FFFEFB
H'FFFEFC
H'FFFEFD
H'FFFEFF