AM79C930 datasheet(86/161 Pages) AMD

86 / 161 page

AMD

P R E L I M I N A R Y

Am79C930

Transceiver Attachment Interface

Registers (TIR Space)

The Transceiver Attachment Interface (TAI) Unit con-

tains a total of 64 registers. Thirty-two of the registers

are directly accessible from the 80188 embedded core

and from the system interface through the BIU. The

other 32 registers are indirectly accessed by first writing

an INDEX value into the TCR Index Register (TIR24)

and then executing a read or write operation to the TCR

Data Port (TIR25). Since the indirectly accessible regis-

ters are used mostly for TAI configuration purposes, this

set of registers is labeled TAI Configuration Registers

(TCR). The following section describes the directly ac-

cessible registers of the TAI, or TIR.

The set of 64 TAI registers is intended primarily for use

by the 80188 firmware. However, access through the

system interface bus to the TAI register set is provided

to allow for direct access by driver code for diagnostic

and other purposes.

The exact location of the TIR register set as viewed from

the system interface will depend upon the choice of

mapping scheme as indicated by the Expand I/O Win-

dow bit (bit 2 of the BSS register (SIR1)). The following

tables give the address for each of the directly accessi-

ble TIRs for each of the system interface modes for each

of the two mapping schemes, as well as the address for

each register as it appears in the memory map of the

80188 embedded core.

AM79C930 Datasheet(PDF) 86 Page - Advanced Micro Devices