23
COMMERCIAL AND INDUSTRIAL
TEMPERATURE RANGES
IDT72T4088/98/108/118 2.5V HIGH-SPEED TeraSync™ DDR/SDR FIFO 40-BIT
CONFIGURATION 16,384 x 40, 32,768 x 40, 65,536 x 40 and 131,072 x 40
FEBRUARY 13, 2009
TABLE 7 — BUS-MATCHING WRITE TO READ RATIO (CONTINUED)
TWO WRITE TO ONE READ (2:1)
Configuration
WSDR RSDR BM IW OW
LHLLL
x40 SDR Input to x40 DDR Output
SDR Write Clock x40 Data In DDR Read Clock x40 Data Out
Positive Edge 1 D[39:0] <= LW1 Positive Edge 1 Q[39:0] <= LW1
Positive Edge 2 D[39:0] <= LW2 Negative Edge 1 Q[39:0] <= LW2
Configuration
WSDR RSDR BM IW OW
HHHHL
x20 DDR Input to x40 DDR Output
DDR Write Clock x20 Data In DDR Read Clock x40 Data Out
Positive Edge 1 D[19:0] <= W1 Positive Edge 1 Q[39:20] <= W1
Negative Edge 1 D[19:0] <= W2 Q[19:0] <= W2
Positive Edge 2 D[19:0] <= W3 Negative Edge 1 Q[39:20] <= W3
Negative Edge 2 D[19:0] <= W4 Q[19:0] <= W4
Configuration
WSDR RSDR BM IW OW
LLHHL
x20 SDR Input to x40 SDR Output
SDR Write Clock x20 Data In SDR Read Clock x40 Data Out
Positive Edge 1 D[19:0] <= W1 Positive Edge 1 Q[39:20] <= W1
Positive Edge 2 D[19:0] <= W2 Q[19:0] <= W2
Configuration
WSDR RSDR BM IW OW
HLHHH
x10 DDR Input to x40 SDR Output
DDR Write Clock x10 Data In SDR Read Clock x40 Data Out
Positive Edge 1 D[9:0] <= B1 Positive Edge 1 Q[39:30] <= B1
Negative Edge 1 D[9:0] <= B2 Q[29:20] <= B2
Positive Edge 2 D[9:0] <= B3 Q[19:10] <= B3
Negative Edge 2 D[9:0] <= B4 Q[9:0] <= B4
FOUR WRITE TO ONE READ (4:1)
Configuration
WSDR RSDR BM IW OW
LHHHL
x20 SDR Input to x40 DDR Output
SDR Write Clock x20 Data In DDR Read Clock x40 Data Out
Positive Edge 1 D[19:0] <= W1 Positive Edge 1 Q[39:20] <= W1
Positive Edge 2 D[19:0] <= W2 Q[19:0] <= W2
Positive Edge 3 D[19:0] <= W3 Negative Edge 1 Q[39:20] <= W3
Positive Edge 4 D[19:0] <= W4 Q[19:0] <= W4
Configuration
WSDR RSDR BM IW OW
HHHHH
x10 DDR Input to x40 DDR Output
DDR Write Clock x10 Data In DDR Read Clock x40 Data Out
Positive Edge 1 D[9:0] <= B1 Positive Edge 1 Q[39:30] <= B1
Negative Edge 1 D[9:0] <= B2 Q[29:20] <= B2
Positive Edge 2 D[9:0] <= B3 Q[19:10] <= B3
Negative Edge 2 D[9:0] <= B4 Q[9:0] <= B4
Positive Edge 3 D[9:0] <= B5 Negative Edge 2 Q[39:30] <= B5
Negative Edge 3 D[9:0] <= B6 Q[29:20] <= B6
Positive Edge 4 D[9:0] <= B7 Q[19:10] <= B7
Negative Edge 4 D[9:0] <= B8 Q[9:0] <= B8
Configuration
WSDR RSDR BM IW OW
LLHHH
x10 SDR Input to x40 SDR Output
SDR Write Clock x10 Data In SDR Read Clock x40 Data Out
Positive Edge 1 D[9:0] <= B1 Positive Edge 1 Q[39:30] <= B1
Positive Edge 2 D[9:0] <= B2 Q[29:20] <= B2
Positive Edge 3 D[9:0] <= B3 Q[19:10] <= B3
Positive Edge 4 D[9:0] <= B4 Q[9:0] <= B4
