45
COMMERCIAL AND INDUSTRIAL
TEMPERATURE RANGES
IDT72T3645/55/65/75/85/95/105/115/125 2.5V TeraSync
™™
™™
™ 36-BIT FIFO
1K x 36, 2K x 36, 4K x 36, 8K x 36, 16K x 36, 32K x 36, 64K x 36, 128K x 36 and 256K x 36
FEBRUARY 4, 2009
Figure 19. Retransmit from Mark (First Word Fall Through Mode)
t
REF
t
ENS
t
ENH
5907 drw24
t
ENS
W
MK-1
WCLK
RCLK
REN
RT
OR
PAF
HF
PAE
Q
n
12
1
t
PAFS
t
REF
2
WEN
t
ENS
t
A
t
ENS
W
MK
W
MK+1
t
A
t
A
W
MK+n
t
A
W
MK+1
W
MK+2
t
A
t
ENS
MARK
t
ENH
t
ENS
t
PAES
(6)
t
A
t
SKEW2
W
MK
t
A
t
HF
3
NOTES:
1. Retransmit setup is complete when OR returns LOW.
2. OE = LOW;RCS = LOW.
3. RT must be HIGH when reading from FIFO.
4. Once MARK is set, the write pointer will not increment past the ‘marked’ location, preventing overwrites of Retransmit data.
5. Before a “MARK” can be set there must be at least x number of bytes of data between the Write Pointer and Read Pointer locations. x = 32 for the IDT72T3645/72T3655/72T3665/72T3675/72T3685/72T3695, x = 128 for the
IDT72T36105/72T36115, x = 256 for the IDT72T36125. Remember, 4 (x9) bytes = 2 (x18) words = 1 (x36) long word.
6. A transition in the PAE flag may occur one RCLK cycle earlier than shown, (on cycle 2).
