8.3.13Poll Register (POLL, Offset 24h) (Master Mode)

When the Poll Register is read, the current interrupt is acknowledged and the next interrupt takes its place in the Poll Register.

The Poll Status Register mirrors the current state of the Poll Register, but the Poll Status Register can be read without affecting the current interrupt request.

Figure 8-16 Poll Register (POLL, offset 24h)

15

7

0

Reserved

S4–S0

IREQ

Bit 15: Interrupt Request (IREQ)—Set to 1 if an interrupt is pending. When this bit is set to 1, the S4–S0 field contains valid data.

Bits 14–5: Reserved —Set to 0.

Bits 4–0: Poll Status (S4–S0)—Indicates the interrupt type of the highest priority pending interrupt. Reading the Poll Register acknowledges the highest priority pending interrupt and enables the next interrupt to advance into the register.

Although the IS bit is set, the interrupt service routine does not begin execution automatically. The application software must execute the appropriate ISR.

Interrupt Control Unit

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AMD Am188TMER, Am186TMER user manual Poll Register POLL, Offset 24h Master Mode, Poll Register POLL, offset 24h