COM20020I-HT SMSC, COM20020I-HT Datasheet - Page 49

• Manufacturer Part Number: COM20020I-HT
• Description: Network Controller & Processor ICs ARCNET Contrllr
• Manufacturer: SMSC

Specifications of COM20020I-HT

• Product: Controller Area Network (CAN)
• Number Of Transceivers: 1
• Data Rate: 5 Mbps
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 4.5 V
• Supply Current (max): 40 mA
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Mounting Style: SMD/SMT
• Package / Case: TQFP-48
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

SMSC COM20020I 3.3V Rev.E
5Mbps ARCNET (ANSI 878.1) Controller with 2K x 8 On-Chip RAM
AD0-AD2,
D3-D7
nWR
nCS
ALE
nRD
Figure 12 - Multiplexed Bus, 80xx-Like Control Signals; Read Cycle
Note 1:
Note 2:
Note 3:
*
PLCC Package: Must be RBUSTMG bit = 0,
TQFP Package: Must be BUSTMG pin = HIGH and RBUSTMG bit =0
T
T
T
T
t10
t11
t12
t13
ARB
ARB
ARB
opr
t8
t9
t1
t2
t3
t4
t5
t6
t7
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
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.
nCS Hold from ALE Low
nRD High to Data High Impedance
Cycle Time (nRD Low to Next Time Low)
Read cycle for Address Pointer Low/High Registers occurring after a read from
Data Register requires a minimum of 5T
leading edge of the next nRD.
Read cycle for Address Pointer Low/High Registers occurring after a write to
Data Register requires a minimum of 5T
leading edge of nRD.
Address Hold from ALE Low
nCS Setup to ALE Low
ALE Low to nRD Low
nRD Low to Valid Data
ALE High Width
ALE Low Width
nRD Low Width
nRD High Width
nWR
Address Setup to ALE Low
opr
t9
to nRD Low
t1
if SLOW ARB = 1
VALID
opr
t3
if SLOW ARB = 0
t13
MUST BE: RBUSTMG bit = 0
t4
t2,
Parameter
Note 3
DATASHEET
t5
Page 49
t6
ARB
ARB
from the trailing edge of nRD to the
from the trailing edge of nWR to the
t10
t11
VALID DATA
4T
min
20
10
10
10
15
20
20
60
20
20
ARB
t8
0
*
max
40
20
t7
Note 2
units
t12
nS
nS
nS
nS
nS
nS
nS
nS
nS
nS
nS
nS
nS
Revision 09-11-06