Texas Instruments TMS380C26 User Manual
Page 54
TMS380C26
NETWORK COMMPROCESSOR
SPWS010A–APRIL 1992–REVISED MARCH 1993
POST OFFICE BOX 1443
•
HOUSTON, TEXAS
77251–1443
54
PARAMETER MEASUREMENT INFORMATION
token ring — ring interface timing
No.
PARAMETER
MIN
TYP
MAX
UNIT
153
Period of RCLK (see Note 14)
4Mbps
125
ns
153
Period of RCLK (see Note 14)
16 Mbps
31.25
ns
154L
Pulse duration of RCLK low
4 Mbps nominal: 62.5 ns
46
ns
154L
Pulse duration of RCLK low
16 Mbps nominal: 15.625 ns
15
ns
154H
Pulse duration of RCLK high
4 Mbps nominal: 62.5 ns
35
ns
154H
Pulse duration of RCLK high
16 Mbps nominal: 15.625 ns
8
ns
155
Setup of RCVR valid before rising edge (1.8 V) of RCLK at 16 Mbps
10
ns
156
Hold of RCVR valid after rising edge (1.8 V) of RCLK at 16 Mbps
4
ns
158L
Pulse duration of ring baud clock low
4 Mbps
40
ns
158L
Pulse duration of ring baud clock low
16 Mbps
15
ns
158H
Pulse duration of ring baud clock high
4 Mbps
40
ns
158H
Pulse duration of ring baud clock high
16 Mbps
8
ns
165
Period of OSCOUT and PXTALIN (see Note 14)
4 Mbps
125
ns
165
Period of OSCOUT and PXTALIN (see Note 14)
16 Mbps (for PXTALIN only)
31.25
ns
166
Tolerance of PXTALIN input frequency (see Note 14)
±
0.01
%
NOTE 14: This parameter is not tested but is required by the IEEE 802.5 specification.
PXTALIN
OSCOUT,
RCVR
RCLK
158L
155
154L
156
154H
153
Valid
158H
165
Figure 19. Token Ring — Ring Interface Timing