Specifications

S1C62N82 TECHNICAL SOFTWARE EPSON II-93

CHAPTER 4: SUMMARY OF PROGRAMMING POINTS

– Be sure to reset the interrupt factor flag before setting to

the EI state on the interrupt processing routine. The

interrupt factor flag is reset by reading through the

software. Not resetting the interrupt factor flag and

interrupt mask register being "1", will cause the same

interrupt to occur again.

– The interrupt factor flag will be reset by reading through

the software. Because of this, when multiple interrupt

factor flags are to be assigned to the same address,

perform the flag check after the contents of the address

has been stored in the RAM. Direct checking with the

FAN instruction will cause all the interrupt factor flag to

be reset.

– Reading of interrupt factor flags is available at EI, but be

careful in the following cases. If the interrupt mask

to be read is set to 1, an interrupt request will be gener-

ated by the interrupt factor flags set timing, or an inter-

rupt request will not be generated. Be very careful when

interrupt factor flags are in the same address.

– Be sure to perform the interrupt mask register writing

while in the DI (interrupt flag = "0") state. Writing while in

the EI (interrupt flag = "1") state may cause mis-opera-

tion.

– In case multiple interrupts occur simultaneously, inter-

rupt processing will be done in the order of high priority

first.

• Vacant Register and

Read/Write

Writing data into the addresses where read/write bits

and read only bits are mixed in 1 word (4 bits) does not

affect the read only bits.