XRT75R12_07 Datasheet, PDF (50/90 Pages) Exar Corporation – TWELVE CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT WITH JITTER

XRT75R12
TWELVE CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT WITH JITTER ATTENUATOR
REV. 1.0.3
5. After the µP toggles the Write signal "Low", the LIU will toggle the RDY output pin "Low". The LIU does this
to inform the µP that the data has been written into the internal register location, and that it is ready for the
next command.
6. The CS input pin must be pulled "High" before a new command can be issued.
FIGURE 35. ASYNCHRONOUS µP INTERFACE SIGNALS DURING PROGRAMMED I/O READ AND WRITE OPERATIONS
Addr[7:0]
CS
D[7:0]
RD
WR
RDY
READ OPERATION
t₀
Valid Address
WRITE OPERATION
t₀
Valid Address
Valid Data for Readback
t₁
t₂
Data Available to Write Into the LIU
t₃
t₄
TABLE 15: ASYNCHRONOUS TIMING SPECIFICATIONS
SYMBOL
PARAMETER
MIN
t₀
Valid Address to CS Falling Edge
0
t₁
CS Falling Edge to RD Assert
0
t₂
RD Assert to RDY Assert
-
NA
RD Pulse Width (t₂)
70
t₃
CS Falling Edge to WR Assert
0
t₄
WR Assert to RDY Assert
-
NA
WR Pulse Width (t₄)
70
MAX
-
-
65
-
-
65
-
UNITS
ns
ns
ns
ns
ns
ns
ns
47