PMC-Sierra, Inc.
PM73488 QSE
L
PMC-980616
Issue 3
5 Gbit/s ATMSwitch Fabric Element
Released
Datasheet
89
8.4
Timing for the CTRL_IN, STAT_OUT, TEST_MODE, IDDTN and DEBUG(1:0) signals is shown in Table 29.
Miscellaneous Timing
Figure 40 shows the reset pin (RESET) timing. The RESET signal must be asserted for a minimum time (
Tres
) to be
properly processed internal to the QSE. The QSE remains in reset while RESET is asserted, and starts performing
normally after
Trstproc
.
a. For the phase aligners to lock.
b. In real applications the output skew will be lower than 1.9ns. The reason for this is as follows. When all
pins are equally loaded, SE_SOC_OUT is faster than all the SE_D_OUTs by (upto) 1.9ns. However, in real
applications SE_SOC_OUT will have fan-out of four, and hence will be loaded four times as much as the
other pins. This will slow down SE_SOC_OUT and hence lower the output skew.
Table 29.
CTRL_IN, STAT_OUT, TEST_MODE and DEBUG Timing
Symbol
Parameter
Signals
Min
Max
Unit
Tdasu
Control signal setup
STAT_OUT (when it behaves as i/p)
4
ns
Tdasu
Control signal setup
CTRL_IN
4
ns
Tdaho
Control signal setup
TEST_MODE
10
ns
Tdaho
Control signal setup
IDDTN
10
ns
Tdaho
Control signal hold
STAT_OUT (when it behaves as i/p)
0
ns
Tdaho
Control signal hold
CTRL_IN
0
ns
Tdaho
Control signal hold
TEST_MODE
10
ns
Tdaho
Control signal hold
IDDTN
10
ns
Tdaq
Output delay from SE_CLK
STAT_OUT (when it behaves as o/p)
1
10
ns
Tdeq
Output delay from SE_CLK
DEBUG(1,0),
1.5
14
ns
Figure 40. Reset Timing
Symbol
Parameter
Signals
Min
Max
Unit
Tres
Reset assertion time
RESET
10
SE_CLK periods
Trstproc
Reset processing time
RESET
2
3
SE_CLK periods
Trstproc
Tres
SE_CLK
RESET
CELL_START(i)