TI380C30 Datasheet, PDF (27/78 Pages) Texas Instruments – INTEGRATED TOKEN-RING COMMPROCESSOR AND PHYSICAL-LAYER INTERFACE

TI380C30
INTEGRATED TOKEN-RING
COMMPROCESSOR AND PHYSICAL-LAYER INTERFACE
SPWS016A – NOVEMBER 1994 – REVISED JULY 1995
SIFACL control for pseudo-DMA operation
Pseudo DMA operation is software controlled by using five bits in the SIFACL register. The logic model for the
SIFACL-register control of pseudo-DMA operation is shown in Figure 5.
Internal
Signals
SYSTEM_INTERRUPT
(SIFSTS register)
DMA
Request
DMA
Grant
DMADIR
Motorola Mode
Host
Interface
M
U
SINTR / SIRQ
X
M
U
SHRQ / SBRQ
X
M
SHLDA / SBGR
U
X
. . . _SWHLDA
SWDDIR SWHRQ ^{. . .} PSDMAEN SINTEN ^{. . .}
SIFACL Register
Figure 5. Pseudo-DMA Logic Related to SIFACL Bits
SDDIR
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