8.4.6In-Service Register (INSERV, Offset 2Ch) (Slave Mode)

The format of the In-Service Register is shown in Figure 8-22.The bits in the In-Service Register are set by the interrupt controller when the interrupt is taken. The in-service bits are cleared by writing to the End-of-Interrupt (EOI) Register.

Figure 8-22 In-Service Register (INSERV, offset 2Ch)

15

7

0

Reserved

TMR2 D1 Res

TMR1 D0 TMR0

The INSERV Register is set to 0000h on reset.

Bits 15–6: Reserved

Bits 5–4: Timer 2/Timer 1 Interrupt In-Service (TMR2–TMR1) —When set to 1, these bits indicate that the corresponding timer interrupt is currently being serviced.

Bits 3–2: DMA Channel Interrupt In-Service (D1–D0) —When set to 1, the corresponding DMA channel is currently being serviced.

Bit 1: Reserved

Bit 0: Timer 0 Interrupt In-Service(TMR0)—When set to 1, this bit indicates Timer 0 is currently being serviced.

Interrupt Control Unit

8-33

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AMD Am188TMER, Am186TMER In-Service Register INSERV, Offset 2Ch Slave Mode, In-Service Register INSERV, offset 2Ch