IA186EM_04 Datasheet, PDF (45/133 Pages) InnovASIC, Inc – 8/16-Bit Microcontrollers

IA186EM/IA188EM
8/16-BIT Microcontrollers
Data Sheet
As of Production Version -03
Master Mode
The In Service flags of the In-Service register are reset when a write is made to the EOI register.
The interrupt service routine (ISR) should write to the EOI to reset the IS bit, in the In-Service register,
for the interrupt before executing an IRET instruction that ends an interrupt service routine.
The specific EOI reset is the preferred method for resetting the IS bits as it is most secure.
The EOI register is write-only.
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
NSPEC
Reserved
S4 – S0
NSPEQ (bit 15) – Non-Specific EOI. This bit is set to 1 a non-specific EOI and when set to 0 it
indicates the specific EOI.
Reserved (bits 14-5)
S [4:0] (bit 4-0) – Source Interrupt Type. These bits show the interrupt type of the highest priority
pending interrupt.
EOI (022h) – Specific End-Of-Interrupt Register.
Slave Mode
An In Service flag of a specific priority, in the In-Service register, is reset when a write is made to the
EOI register.
A three-bit user supplied priority-level value that points to the in-service bit that is to be reset. Writing
this value to this register resets the specific bit.
The EOI register is write only and undefined at reset.
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
0
0 0 0 0 0 0 000 0 0 0
L2 – L0
Reserved (bits 15-3) – Write as 0.
L[2:0] (bit 2-0) – Interrupt Type. The priority or the IS (interrupt service) bit to be reset is encoded in
these three bits. Writing to these bits caused the issuance of an EOI for the interrupt type. See Table
3 - Interrupt Types.
INTVEC (020h) –INTerrupt VECtor Register.
Slave Mode
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