HD64F3437TFI16V Renesas Electronics America, HD64F3437TFI16V Datasheet - Page 114

• Manufacturer Part Number: HD64F3437TFI16V
• Description: MCU FLASH 60K 100-TQFP
• Manufacturer: Renesas Electronics America

Specifications of HD64F3437TFI16V

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

4.4
In word access, the least significant bit of the address is always assumed to be 0. The stack is
always accessed by word access. Care should be taken to keep an even value in the stack pointer
(general register R7). Use the PUSH and POP (or MOV.W Rn, @–SP and MOV.W @SP+, Rn)
instructions to push and pop registers on the stack.
Setting the stack pointer to an odd value can cause programs to crash. Figure 4.9 shows an
example of damage caused when the stack pointer contains an odd address.
82
SP
Note on Stack Handling
Figure 4.9 Example of Damage Caused by Setting an Odd Address in R7
PC
PC
R1
SP:
H'FECF set in SP
L
H
L
:
:
:
Upper byte of program counter
Lower byte of program counter
General register
Stack pointer
BSR instruction
SP
PC is improperly stored
beyond top of stack
PC
PC
H
L
MOV.B R1L, @–R7
SP
PC
R1
PC
H
is lost
L
L
H'FECC
H'FECD
H'FECF