Instructions That Disable Interrupts; Interrupts During Execution Of Eepmov Instruction - Hitachi H8S/2199 Hardware Manual

6.5.2

Instructions that Disable Interrupts

Instructions that disable interrupts are LDC, ANDC, ORC, and XORC. After any of these
instructions is executed, all interrupts including NMI are disabled and the next instruction is
always executed. When the I bit or UI bit is set by one of these instructions, the new value
becomes valid two states after execution of the instruction ends.
6.5.3

Interrupts during Execution of EEPMOV Instruction

Interrupt operation differs between the EEPMOV.B instruction and the EEPMOV.W instruction.
With the EEPMOV.B instruction, an interrupt request (including NMI) issued during the transfer
is not accepted until the move is completed.
With the EEPMOV.W instruction, if an interrupt request is issued during the transfer, interrupt
exception handling starts at a break in the transfer cycle. The PC value saved on the stack in this
case is the address of the next instruction.
Therefore, if an interrupt is generated during execution of an EEPMOV.W instruction, the
following coding should be used.
L1: EEPMOV.W
MOV.W R4,R4
BNE L1
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