HD64F3437TF16 Datasheet, PDF(111/752 Page) Hitachi Semiconductor – 12 V must not be applied to the S-mask model (single-power-supply specification), as this may permanently damage the device.

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HD64F3437TF16 Datasheet, PDF (111/752 Pages) Hitachi Semiconductor – 12 V must not be applied to the S-mask model (single-power-supply specification), as this may permanently damage the device.

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4.4 Note on Stack Handling

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, @âSP 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.

PCH

SP

PCL

SP

R1L

H'FECC

PCL

H'FECD

SP

H'FECF

BSR instruction

MOV.B R1L, @âR7

H'FECF set in SP

PC is improperly stored

beyond top of stack

PCH is lost

PCH: Upper byte of program counter

PCL: Lower byte of program counter

R1L: General register

SP: Stack pointer

Figure 4.9 Example of Damage Caused by Setting an Odd Address in R7

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