IDT72T7285/72T7295/72T72105/72T72115 2.5V TeraSync
16,384 x 72, 32,768 x 72, 65,536 x 72, 131,072 x 72
72-BIT FIFO
COMMERCIAL AND INDUSTRIAL
TEMPERATURE RANGES
and read pointer when the MARK is asserted. (32 bytes = 16 word = 8 long
words).Also,oncetheMARKisset,thewritepointerwillnotincrementpastthe
“marked”locationuntiltheMARKisdeasserted.Thisprevents“overwriting”of
retransmitdata.
Onceamarkedlocationhasbeenset(andthedeviceisstillinretransmitmode,
MARKisHIGH),aretransmitcanbeinitiatedbyarisingRCLKedgewhilethe
retransmit input (RT) is LOW. REN must be HIGH (reads disabled) before
bringingRTLOW.Thedeviceindicatesthestartofretransmitsetupbysetting
OR HIGH.
WhenOR goes LOW, retransmitsetupis complete andonthe nextrising
RCLKedgeafterretransmitsetupiscomplete,(RTgoesHIGH),thecontents
ofthefirstretransmitlocationareloadedontotheoutputregister.SinceFWFT
modeisselected,thefirstwordappearsontheoutputsregardlessofREN,a
LOWonRENisnotrequiredforthefirstword.Readingallsubsequentwords
requires a LOW on REN to enable the rising RCLK edge. See Figure 19,
RetransmitfromMarktiming(FWFTmode),fortherelevanttimingdiagram.
Note,theremustbeaminimumof32bytesofdatabetweenthewritepointer
HSTL/LVTTL I/O
BoththewriteportandreadportareuserselectablebetweenHSTLorLVTTL
I/O,viatwoselectpins,WHSTLandRHSTLrespectively.Allothercontrolpins
are selectable via SHSTL, see Table 5 for details of groupings.
Note,thatwhenthewriteportisselectedforHSTLmode,theusercanreduce
thepowerconsumption(instand-bymodebyutilizingtheWCSinput).
All “Static Pins” must be tied to VCC or GND. These pins are LVTTL only,
andare purelydevice configurationpins.
TABLE 5 — I/O CONFIGURATION
WHSTL SELECT
RHSTL SELECT
SHSTL SELECT
STATIC PINS
WHSTL: HIGH = HSTL
LOW = LVTTL
RHSTL: HIGH = HSTL
LOW = LVTTL
SHSTL: HIGH = HSTL
LOW = LVTTL
LVTTL ONLY
Dn (I/P)
RCLK/RD (I/P)
RCS (I/P)
MARK (I/P)
REN (I/P)
OE (I/P)
EF/OR (O/P)
SCLK (I/P)
LD (I/P)
MRS (I/P)
TCK (I/P)
TMS (I/P)
SEN (I/P)
FWFT/SI (I/P)
PRS (I/P)
IW (I/P)
BM (I/P)
OW (I/P)
ASYW (I/P)
BE (I/P)
FSEL0 (I/P)
PFM (I/P)
WHSTL (I/P)
WCLK/WR (I/P)
WEN (I/P)
WCS (I/P)
PAF (O/P)
EREN (O/P)
PAE (O/P)
FF/IR (O/P)
HF (O/P)
TRST (I/P)
TDI (I/P)
ASYR (I/P)
IP (I/P)
FSEL1 (I/P)
SHSTL (I/P)
RHSTL (I/P)
RT (I/P)
Qn (O/P)
ERCLK (O/P)
TDO (O/P)
20
IDT [ INTEGRATED DEVICE TECHNOLOGY ]
