AMD Am186TMER Bits 15-3 Reserved -Write as, Specific End-of-Interrupt Register EOI, offset 22h

8.4.9Specific End-of-Interrupt Register (EOI, Offset 22h) (Slave Mode)

In Slave mode, a write to the EOI Register resets an in-service bit of a specific priority. The user supplies a three-bit priority-level value that points to an in-service bit to be reset. The command is executed by writing the correct value in the Specific EOI Register at offset 22h.

Figure 8-25 Specific End-of-Interrupt Register (EOI, offset 22h)

15 7 0

0 0 0 0 0 0 0 0 0 0 0 0 0

L2–L0

The EOI Register is undefined on reset.

Bits 15–3: Reserved —Write as 0.

Bits 2–0: Interrupt Type (L2–L0)—Encoded value indicating the priority of the IS (interrupt service) bit to be reset. Writes to these bits cause an EOI to be issued for the interrupt type in Slave mode. Write-only register.

8-36 Interrupt Control Unit