MT8920B Mitel Networks Corporation, MT8920B Datasheet - Page 19

• Manufacturer Part Number: MT8920B
• Description: ISO-cmos St-bus Family St-bus Parallel Access Circuit
• Manufacturer: Mitel Networks Corporation

CONDITION 1:
CONDITION 2:
CONDITION 3:
CONDITION 4:
OE, R/W
OE, R/W
OE, R/W
OE, R/W
A0 - A5
BUSY
BUSY
BUSY
BUSY
C4i
CS
Access begins before contention window and finishes before ST-BUS access - No contention.
Access begins before contention window and continues into ST-BUS access.
Access begins during ST-BUS access
Access begins within contention window but before ST-BUS access.
READ ADDRESS N or WRITE ADDRESS (N + 1)
CHANNEL N - BIT 0
t
Figure 16 - Mode 2 Access Contention Resolution
EC4L
t
EC4L
CONTENTION WINDOW
t
EBL
t
t
EC4H
C4BL
ST-BUS ACCESS
t
EBL
t
C4BH
(N matches incoming
ST-BUS channel)
CHANNEL (N + 1) - BIT 7
CMOS
MT8920B
t
t
C4BH
C4BH
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