XRT79L73 Datasheet, PDF (58/71 Pages) Exar Corporation – 3 - CHANNEL DS3/E3 ATM UNI/PPP COMBO IC

XRT79L73
REV. P1.0.0
PRELIMINARY
ÿþ
3 - CHANNEL DS3/E3 ATM UNI/PPP COMBO IC
TABLE 9: TIMING INFORMATION FO RTHE TRNASMIT PAYLOAD DATA INPUT INTERFACE BLOCK
Test Conditions: TA = 25°C, VDD = 3.3V + 5% unless otherwise specified
SYMBOL
PARAMETER
MIN. TYP. MAX. UNITS
CONDITIONS
t₁₄ TxNib set-up time to third rising edge of TxInClk
20
ns DS3 Applications
27
ns E3 Applications
t₁₅ Payload Nibble hold time, from latching edge of
0
ns
TxInClk
t₁₆ TxFrameRef set-up time, to latching edge of TxInClk
20
ns DS3 Applications
27
ns E3 Applications
t₁₇ TxFrameRef hold time, from latching edge of TxNib- 0
Clk
t₁₈ TxNibClk to TxNibFrame output delay time
20
Framer IC is
Frame Slave
ns
Framer IC is
Frame Slave
25
ns DS3 Applications
31
ns E3 Applications
FIGURE 11. TIMING DIAGRAM FOR THE TRANSMIT PAYLOAD DATA INPUT INTERFACE WHEN THE XRT79L73 IS
OPERATING IN BOTH THE DS3 AND LOOP-TIMING MODES
XRT79L74 Transmit Payload Data I/F Signals
t3
RxOutClkn
TxSern
TxFramen
TxOH_Indn
Payload[4702] Payload[4703]
X-Bit
t2
t1
Payload[0]
t4
DS3 Frame Number N
DS3 Frame Number N + 1
56