COM20022I-HT Standard Microsystems (SMSC), COM20022I-HT Datasheet - Page 67

• Manufacturer Part Number: COM20022I-HT
• Manufacturer: Standard Microsystems (SMSC)

Specifications of COM20022I-HT

• Operating Supply Voltage (typ): 5V
• Operating Supply Voltage (min): 4.5V
• Operating Supply Voltage (max): 5.5V
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 48
• Lead Free Status / Rohs Status: Compliant

10 Mbps ARCNET (ANSI 878.1) Controller with 2Kx8 On-Chip RAM
Datasheet
SMSC COM20022I
nIOCS16
D0-D15
**
Note 3: Write cycle for Address Pointer Low Register occurring after a read from Data
A0-A2
Notes 2 and 3 are applied to an access to Data Register by DMA transfer.
Note 1:
Note 2: Any cycle occurring after a write to the Address Pointer Low Register
*
***:
**** t11 is measured from the latest active (valid) timing among nCS, A0-A2.
*****
nWR
Figure 8.9 - Non-Multiplexed Bus, 80XX-Like Control Signals; Write Cycle
nRD
nCS
T
T
T
T
t1
t5
t2
t3
t4
t6
t7
t8
t9
t10
t11
t12
ARB
ARB
ARB
opr
be 30 nS measured from the later of nCS falling or Valid Data available.
nCS may become active after control becomes active, but the data setup time will now
t12 is measured from the earliest inactive (invalid) timing among nCS, A0-A2.
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 COM20022 on every other cycle.
Therefore, the cycle time specified in the microcontroller's datasheet
should be doubled when considering back-to-back COM20022 cycles.
Register requires a minimum of 5T
leading edge of nWR.
requires a minimum of 4T
of the next 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.
Address Setup to nWR Active
Cycle Time (nWR
Address Hold from nWR Inactive
nCS Setup to WR Active
nCS Hold from nWR Inactive
Valid Data Setup to nWR High
Data Hold from nWR High
nWR Low Width
nWR High Width
nRD
nIOCS16 Output Delay from nCS Low
nIOCS16 Hold Delay from nCS High
opr
to nWR Low
if SLOW ARB = 1
Parameter
Note 3
opr
t10
t1
if SLOW ARB = 0
CASE 1: BUSTMG pin = HIGH
t3
DATASHEET
to Next
t11
ARB
from the trailing edge of nWR to the leading edge
ARB
ARB
)**
Page 67
VALID
from the trailing edge of nRD to the
from the trailing edge of nWR to the
t8
VALID DATA
VALID VALUE
4T
0*****
t6
30***
min
15
10
10
20
20
20
ARB
5
0
*
40****
max
t7
t2
Note 2
t4
t9
t5**
units
nS
nS
nS
nS
nS
nS
nS
nS
nS
nS
nS
nS
t12
t5
Revision 09-27-07