COMMERCIAL TEMPERATURE RANGE
IDT72V3684/72V3694/72V36104 3.3V CMOS SyncBiFIFO
TM
WITH
BUS-MATCHING 16,384 x 36 x 2, 32,768 x 36 x 2, 65 and 536 x 36 x 2
5
Symbol Name I/O Description
FS0/SD Flag Offset Select 0/ I FS1/SEN and FS0/SD are dual-purpose inputs used for flag offset register programming. During Master
Serial Data Reset, FS1/SEN and FS0/SD, together with FS2, select the flag offset programming method. Three offset
register programming methods are available: automatically load one of five preset values (8, 16, 64, 256 or
1,024), parallel load from Port A, and serial load.
FS1/SEN Flag Offset Select 1/ I
Serial Enable, When serial load is selected for flag offset register programming, FS1/SEN is used as an enable
synchronous to the LOW-to-HIGH transition of CLKA. When FS1/SEN is LOW, a rising edge on CLKA load
FS2
(1)
Flag Offset Select 2 I the bit present on FS0/SD into the X and Y registers. The number of bit writes required to program the offset
registers is 56 for the IDT72V3684, 60 for the IDT72V3694, and 64 for the IDT72V36104. The first bit write
stores the Y- register (Y1) MSB and the last bit write stores the X-register (X2) LSB.
MBA Port A Mailbox I A HIGH level on MBA chooses a mailbox register for a Port A read or write operation. When the A0-A35
Select outputs are active, a HIGH level on MBA selects data from the mail2 register for output and a LOW level
selects FIFO2 output register data for output.
MBB Port B Mailbox I A HIGH level on MBB chooses a mailbox register for a Port B read or write operation. When the B0-B35
Select outputs are active, a HIGH level on MBB selects data from the mail1 register for output and a LOW level
selects FIFO1 output register data for output.
MBF1 Mail1 Register O MBF1 is set LOW by a LOW-to-HIGH transition of CLKA that writes data to the mail1 register. Writes to the mail1
Flag register are inhibited while MBF1 is LOW. MBF1 is set HIGH by a LOW-to-HIGH transition of CLKB when a
Port B read is selected and MBB is HIGH. MBF1 is set HIGH following either a Master or Partial Reset of FIFO1.
MBF2 Mail2 Register O MBF2 is set LOW by a LOW-to-HIGH transition of CLKB that writes data to the mail2 register. Writes to the mail2
Flag register are inhibited while MBF2 is LOW. MBF2 is set HIGH by a LOW-to-HIGH transition of CLKA when a Port
A read is selected and MBA is HIGH. MBF2 is set HIGH following either a Master or Partial Reset of FIFO2.
MRS1 FIFO1 Master I A LOW on this pin initializes the FIFO1 read and write pointers to the first location
of memory and sets the Port
Reset
B output register to all zeroes. A LOW-to-HIGH transition
on MRS1 selects the programming method (serial or parallel)
and one of five programmable flag default offsets for FIFO1 and FIFO2. It also configures Port B for bus size and
endian arrangement. Four LOW-to-HIGH transitions of CLKA and four LOW-to-HIGH transitions of CLKB must
occur while MRS1 is LOW.
MRS2 FIFO2 Master I A LOW on this pin initializes the FIFO2 read and write pointers to the first location of memory and sets the Port A
Reset output register to all zeroes. A LOW-to-HIGH transition on MRS2, toggled simultaneously with MRS1, selects the
programming method (serial or parallel) and one of the programmable flag default offsets for
FIFO2. Four LOW-to-
HIGH transitions of CLKA and four LOW-to-HIGH transitions
of CLKB must occur while MRS2 is LOW.
PRS1/ Partial Reset/ I This pin is muxed for both Partial Reset and Retransmit operations, it is used in conjunction with the RTM pin.
RT1 Retransmit FIFO1 If RTM is in a LOW condition, a LOW on this pin performs a Partial Reset on FIFO1 and initializes the FIFO1 read
and write pointers to the first location of memory and sets the Port B output register to all zeroes. During Partial Reset,
the currently selected bus size, endian arrangement, programming method (serial or parallel), and programmable
flag settings are all retained. If RTM is HIGH, a LOW on this pin performs a Retransmit and initializes the FIFO1 read
pointer only to the first memory location.
PRS2/ Partial Reset/ I This pin is muxed for both Partial Reset and Retransmit operations, it is used in conjunction with the RTM pin.
RT2 Retransmit FIFO2 If RTM is in a LOW condition, a LOW on this pin performs a Partial Reset on FIFO2 and initializes the FIFO2 read
and write selected bus size, endian arrangement, programming method (serial or parallel), and programmable flag
settings are all retained. If RTM is HIGH, a LOW on this pin performs a Retransmit and initializes the FIFO2 read pointer
only to the first memory location.
RTM Retransmit Mode I This pin is used in conjunction with the RT1 and RT2 pins. When RTM is HIGH a Retransmit is performed on
FIFO1 or FIFO2 respectively.
SIZE
(1)
Bus Size Select I A HIGH on this pin when BM is HIGH selects byte bus (9-bit) size on Port B. A LOW on this pin when BM is HIGH
selects word (18-bit) bus size. SIZE works with BM and BE to select the bus size and endian arrangement for Port
B. The level of SIZE must be static throughout device operation
W/RA Port-A Write/ I A HIGH selects a write operation and a LOW selects a read operation on Port A for a LOW-to-HIGH
Read Select transition of CLKA. The A0-A35 outputs are in the HIGH impedance state when W/RA is HIGH.
W/RB Port-B Write/ I A LOW selects a write operation and a HIGH selects a read operation on Port B for a LOW-to-HIGH
Read Select transition of CLKB. The B0-B35 outputs are in the HIGH impedance state when W/RB is LOW.
PIN DESCRIPTIONS (CONTINUED)
NOTE:
1. FS2, BM and SIZE inputs are not TTL compatible. These inputs should be tied to GND or VCC.