COM20020ILJP Standard Microsystems (SMSC), COM20020ILJP Datasheet - Page 56

• Manufacturer Part Number: COM20020ILJP
• Manufacturer: Standard Microsystems (SMSC)

Specifications of COM20020ILJP

• Number Of Transceivers: 1
• Operating Supply Voltage (max): 5.5V
• Operating Supply Voltage (typ): 5V
• Operating Supply Voltage (min): 4.5V
• Operating Temperature (max): 85C
• Operating Temperature (min): -40C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 28
• Lead Free Status / RoHS Status: Not Compliant

Revision 12-05-06
AD0-AD2,
nCS
ALE
nWR
D3-D7
nRD
**
*
Note 1:
Note 2:
Note 3:
T
T
T
T
ARB
ARB
ARB
opr
t10
t11
t12
t13
t1
t2
t3
t4
t5
t6
t7
t8
t9
is the period of operation clock. It depends on CKUP1 and CKUP0 bits
is the Arbitration Clock Period
is identical to T
is twice T
Figure 8.4 - Multiplexed Bus, 80XX-Like Control Signals; Write Cycle
Address Setup to ALE Low
Address Hold from ALE Low
nCS Setup to ALE Low
nCS Hold from ALE Low
ALE Low to nDS Low
ALE High Width
ALE Low Width
nWR Low Width
nWR High Width
nRD
Valid Data Setup to nDS High
Data Hold from nDS High
Cycle Time (nWR
Write cycle for Address Pointer Low Register occurring after a write to Data
Register requires a minimum of 5T
leading edge of the next nWR.
Write cycle for Address Pointer Low Register occurring after a read from Data
Register requires a minimum of 5T
leading edge of nWR.
Any cycle occurring after a write to Address Pointer Low Register requires a
next nWR.
The Microcontroller typically accesses the COM20020 on every other cycle.
Therefore, the cycle time specified in the microcontroller's datasheet
should be doubled when considering back-to-back COM20020 cycles.
minimum of 4T
opr
if SLOW ARB = 1
t9
to nWR Low
t1
opr
VALID
t3
if SLOW ARB = 0
t13
ARB
Parameter
Note 3
from the trailing edge of nWR to the leading edge of the
t2,
t4
to Next
t5
DATASHEET
)**
ARB
ARB
Page 56
from the trailing edge of nWR to the
from the trailing edge of nRD to the
t10
t11
VALID DATA
5Mbps ARCNET (ANSI 878.1) Controller with 2K x 8 On-Chip RAM
t6
4T
min
20
20
20
20
20
20
10
10
10
15
30
10
ARB
*
max
t7
Note 2
units
nS
nS
nS
nS
nS
nS
nS
nS
nS
nS
nS
nS
nS
t8**
t12
t8
SMSC COM20020I Rev D
Datasheet