Specifications

Serial Communications (82050)
Interrupt Identify
The ACC includes 10 sources of interrupts prioritized into four
categories. The Interrupt Identify register flags whether or not the
ACC has an interrupt pending and, if so, from which of the four
categories it originated. Figure 11-7 below shows the format for the
Interrupt Identify register.
The IP bit indicates whether an interrupt is pending. A logical 0 in IP
signals an active interrupt, and a logical 1 in IP signals no active
interrupt. The interrupt sources are prioritized into the following four
categories: receiver status, receiver data, transmitter data, and modem
status, in that order. The interrupt ID field, bits 1 and 2, identifies the
interrupt category if there is an active interrupt.
Register:Interrupt Identify
Address:03FAh
Access:Read
76543210
IPN
Interrupt Pending
0 Active interrupt
1 No active interrupt
IID
Interrupt ID
00 ?
01 ?
10 ?
11 ?
RSV
Reserved
RSV
Reserved
RSV
Reserved
RSV
Reserved
RSV
Reserved
Figure 11–7. Interrupt Identify Register.
11-18