TI380C30 Datasheet, PDF (74/78 Pages) Texas Instruments – INTEGRATED TOKEN-RING COMMPROCESSOR AND PHYSICAL-LAYER INTERFACE

SIF Inputs:
SBCLK
SIF Master
T2
T3
Bus Exchange
T4
I1
I2
User
T1
SBGR
SDTACK
SIF Outputs:
230
SBRQ ^†
SAS, SUDS,
SLDS
SRNW
SADH0 – SADH7,
SADL0 – SADL7,
SPH, SPL
SDDIR
Read
Write
SIF
Write
Read
220
240
223b
220
224d
240
Hi-Z
Hi-Z
224b
SOWN
† _{In 80x8x mode, the system interface deasserts SHRQ on the rising edge of SBCLK following the T4 state of the last system-bus transfer it controls. In 68xxx mode, the system}
interface deasserts SBRQ on the rising edge of SBCLK in state T2 of the first system-bus transfer it controls.
Figure 34. 68xxx-Mode Bus-Arbitration Timing, SIF Returns Control