Programming Notes - Epson E0C6006 Technical Manual

TI2
ETI2
TI8
ETI8
TI32
ETI32
IREM
EIREM
IK1
EIK1
IK0
EIK0

4.10.4 Programming notes

(1) Restart from the HALT mode is performed by an interrupt. The return address after completion of the
interrupt processing will be the address following the HALT instruction.
(2) When an interrupt occurs, the interrupt flag will be reset by the hardware and it will become DI
status. After completion of the interrupt processing, set to the EI status through the software as
needed.
Moreover, the nesting level may be set to be programmable by setting to the EI state at the beginning
of the interrupt processing routine.
(3) The interrupt factor flags must always be reset before setting the EI status. When the interrupt mask
register has been set to "1", the same interrupt will occur again if the EI status is set unless of resetting
the interrupt factor flag.
(4) 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.
(5) Reading of interrupt factor flag is available at EI, but be careful in the following cases.
If the interrupt mask register value corresponding to the interrupt factor flag to be read is set to "1", an
interrupt request will be generated by the interrupt factor flag set timing, or an interrupt request will
not be generated. Be very careful when interrupt factor flags are in the same address.
E0C6006 TECHNICAL MANUAL
CHAPTER 4: PERIPHERAL CIRCUITS AND OPERATION (Interrupt and HALT)
Fig. 4.10.3.1 Interrupt request/interrupt vector generation circuit
Interrupt vector
IF
Interrupt factor flag
Interrupt mask register
EPSON
(MSB)
Program
counter
(LSB)
INT
(interrupt request)
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