22
COMMERCIAL AND INDUSTRIAL
TEMPERATURE RANGES
IDT72T2098/108/118/128 2.5V HIGH-SPEED TeraSync™ DDR/SDR FIFO 20-BIT/10-BIT CONFIGURATIONS
32K x 20/64K x 10, 64K x 20/128K x 10, 128K x 20/256K x 10, 256K x 20/512K x 10
FEBRUARY 13, 2009
TABLE 7 — BUS-MATCHING WRITE TO READ RATIO (CONTINUED)
ONE WRITE TO FOUR READ (1:4)
x20 DDR Input to x10 SDR Output
DDR Write Clock x20 Data In SDR Read Clock x10 Data Out
Positive Edge 1 D[19:10] <= B1 Positive Edge 1 Q[9:0] <= B1
Positive Edge 1 D[9:0] <= B2 Positive Edge 2 Q[9:0] <= B2
Negative Edge 1 D[19:10] <= B3 Positive Edge 3 Q[9:0] <= B3
Negative Edge 1 D[9:0] <= B4 Positive Edge 4 Q[9:0] <= B4
TWO WRITE TO ONE READ (2:1)
x20 SDR Input to x20 DDR Output
SDR Write Clock x20 Data In DDR Read Clock x20 Data Out
Positive Edge 1 D[19:0] <= W1 Positive Edge 1 Q[19:0] <= W1
Positive Edge 2 D[19:0] <= W2 Negative Edge 1 Q[19:0] <= W2
x10 DDR Input to x20 DDR Output
DDR Write Clock x10 Data In DDR Read Clock x20 Data Out
Positive Edge 1 D[9:0] <= B1 Positive Edge 1 Q[19:10] <= B1
Negative Edge 1 D[9:0] <= B2 Postive Edge 1 Q[9:0] <= B2
Positive Edge 2 D[9:0] <= B3 Negative Edge 1 Q[19:10] <= B3
Negative Edge 2 D[9:0] <= B4 Negative Edge 1 Q[9:0] <= B4
x10 SDR Input to x20 SDR Output
SDR Write Clock x10 Data In SDR Read Clock x20 Data Out
Positive Edge 1 D[19:10] <= B1 Positive Edge 1 Q[19:10] <= B1
Positive Edge 2 D[9:0] <= B2 Positive Edge 1 Q[9:0] <= B2
x10 SDR Input to x10 DDR Output
DDR Write Clock x10 Data In SDR Read Clock x10 Data Out
Positive Edge 1 D[9:0] <= B1 Positive Edge 1 Q[9:0] <= B1
Positive Edge 2 D[9:0] <= B3 Negative Edge 1 Q[9:0] <= B3
Configuration
WSDR RSDR IW OW
HLLL
FOUR WRITE TO ONE READ (4:1)
x10 SDR Input to x20 DDR Output
SDR Write Clock x10 Data In DDR Read Clock x20 Data Out
Positive Edge 1 D[9:0] <= B1 Positive Edge 1 Q[19:10] <= B1
Positive Edge 2 D[9:0] <= B2 Positive Edge 1 Q[9:0] <= B2
Positive Edge 3 D[9:0] <= B3 Negative Edge 1 Q[19:0] <= B3
Positive Edge 4 D[9:0] <= B4 Negative Edge 1 Q[9:0] <= B4
Configuration
WSDR RSDR IW OW
LHLL
Configuration
WSDR RSDR IW OW
HHHL
Configuration
WSDR RSDR IW OW
LLHL
Configuration
WSDR RSDR IW OW
LHHH
Configuration
WSDR RSDR IW OW
LHHL
