Specifications

12 SAM0023-122898 ESS Technology, Inc.

ES1869 DATA SHEET

BUS INTERFACING

This section discusses interfacing to the PC bus, and

items relating to configuration for the bus.

Table 1 shows the pins used to interface the ES1869 to the

ISA bus.

Table 1 ISA Bus Interface Pins

Pins Descriptions

A[15:12] Dual-purpose pins. A[15:12] are ISA bus address inputs.

A[11:0] ISA bus address inputs.

AEN ISA active-low address enable.

D[7:0] ISA bidirectional data bus.

DRQD Dual-purpose pin. DRQD is a tri-state output. Optional 16-bit DMA request for IDE interface.

DACKBD Dual-purpose pin. DACKBD is an optional 16-bit DMA acknowledge for IDE interface.

DRQ(A-C) Three (A, B, C) active-high DMA requests to the ISA bus. Unselected DRQ outputs are high-impedance. When

DMA is not active, the selected DRQ output has a pull-down device that holds the DRQ line inactive unless another

device that shares the same DRQ line can source enough current to make the DRQ line active. DRQs are software

configurable.

DACKB(A-C) Three (A, B, C) active-low DMA acknowledge inputs.

IRQ(A-F) Six (A, B, C, D, E, F) active-high interrupt requests to the ISA bus. Unselected IRQ outputs are high-impedance.

IRQs are software configurable.

IORB ISA active-low read strobe.

IOWB ISA active-low write strobe.

RESET Active-high. Reset from ISA bus.