XRT86VL3X_07 Datasheet, PDF (147/153 Pages) Exar Corporation – T1/E1/J1 FRAMER/LIU COMBO - ARCHITECTURE DESCRIPTION

XRT86VL3X
REV. 1.2.2
T1/E1/J1 FRAMER/LIU COMBO - ARCHITECTURE DESCRIPTION
MOTOROLA ASYCHRONOUS INTERFACE TIMING
The signals used in the Motorola microprocessor interface mode are: Address Strobe (AS), Data Strobe (DS),
Read/Write Enable (R/W), Chip Select (CS), Address and Data bits. The interface is compatible with the timing
of a Motorola 68000 microprocessor family. The interface timing is shown in Figure 122. The I/O specifications
are shown in Table 27.
FIGURE 122. MOTOROLA ASYCHRONOUS MODE INTERFACE SIGNALS DURING PROGRAMMED I/O READ AND WRITE
OPERATIONS
A LE_ AS
ADDR[6:0]
CS
D ATA[7:0]
RD_DS
W R _R /W
RDY_DTACK
t₀
t₃
t₁
READ OPERATION
Valid Address
Valid Data for Readback
t₂
t₀
t₃
t₁
WRITE OPERATION
Valid Address
Data Available to W rite Into the LIU
t₂
TABLE 27: MOTOROLA ASYCHRONOUS MODE MICROPROCESSOR INTERFACE TIMING SPECIFICATIONS
SYMBOL
PARAMETER
MIN
MAX
UNITS
t₀
Valid Address to CS Falling Edge
0
-
ns
t₁
CS Falling Edge to DS (Pin RD_DS) Assert
0
-
ns
t₂
DS Assert to DTACK Assert
-
320
ns
NA
DS Pulse Width (t₂)
320
-
ns
t₃
CS Falling Edge to AS (Pin ALE_AS) Falling Edge 0
-
ns
140