COM20022I-3V Datasheet, PDF (77/83 Pages) SMSC Corporation – 10 Mbps ARCNET (ANSI 878.1) Controller with 2Kx8 On-Board RAM

10 Mbps ARCNET (ANSI 878.1) Controller with 2Kx8 On-Board RAM
Datasheet
Table 8.1 - DMA Timing
PARAMETER
t1 nDACK Inactive Pulse Width
t2 The First DREQ Assertion Delay After Writing Low
Pointer
t3 DREQ Assert Delay from nREFEX Active at
Programmable Burst Transfer Mode
t4 DREQ Assertion Delay from Write/Read Inactive at
Non-Burst Transfer Mode
t5 DREQ Assertion Delay from nDACK
GTTM
Inactive due to Timeout of Gate Timer at ^{bit =0}
Programmable Burst Transfer Mode
GTTM
bit=1
t6 DREQ Negation Delay from Write/Read Active
t7 DREQ Negation Delay from TC and Write/Read
Active
t8 Data Access Time from Read Active
t9 Data Float Delay from Read Inactive
t10 nREFEX Active Pulse Width
t11 Write Active Pulse Width
CASE
1W
CASE
2W
t12 Read Active Pulse Width
CASE
1R
CASE
2R
t13 Active Pulse Overlap Width between TC and
Write/Read
t14 Write/Read Inactive Pulse Width CASE1w/1R
CASE2w/2R
t15 Write Cycle Interval Period
MIN
4 Tarb
0
0
7Txtl
15Txtl
0
0
0
20
20
65
60
100
20
20
30
4Tarb
t16 Read Cycle Interval Period
CASE1R
CASE2R
t17 Data Setup to Write Inactive
t18 Data Hold From Write Inactive
t19 nCS High Setup to nDACK Active
t20 nCS High Hold from nDACK Inactive
t21 DREQ Active Setup to nDACK Active
t22 DIR Setup to nDS Low (Motorola mode only)
t23 DIR Hold from nDS High (Motorola mode only)
t24 nDACK Setup to Write/Read Active
t25 nDACK Hold After Write/Read Inactive
t26 nREFEX Inactive Time
4Tarb
4Tarb+3
0nS
30
10
20
20
20
10
10
30
5
3Txtl
TYP
5
Tarb
MAX
30
5Tarb
+40ns
40
40
8Txtl
+40ns
16Txtl
+40ns
40
40
40
20
UNIT
ns
NOTE
(Note 8.1)
ns
(Note 8.3)
ns
(Note 8.4)
(Note 8.2)
ns
(Note 8.4)
ns
(Note 8.4)
ns
(Note 8.4)
ns
(Note 8.4)
ns
ns
(Note 8.4,
Note 8.5)
ns
ns
(Note 8.4,
Note 8.5)
ns
ns
(Note 8.4)
ns
(Note 8.4,
ns
Note 8.5)
(Note 8.1,
Note 8.4)
(Note 8.1,
Note 8.4,
Note 8.5)
ns
(Note 8.4)
ns
(Note 8.4)
ns
ns
ns
ns
ns
ns
(Note 8.4)
ns
(Note 8.4)
(Note 8.2)
SMSC COM20022I 3V
Page 77
DATASHEET
Revision 02-27-06