Document
3.3 VOLT CMOS SyncBiFIFOTM 256 x 36 x 2 512 x 36 x 2 1,024 x 36 x 2
.EATURES:
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IDT72V3622 IDT72V3632 IDT72V3642
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Memory storage capacity: IDT72V3622 – 256 x 36 x 2 IDT72V3632 – 512 x 36 x 2 IDT72V3642 – 1,024 x 36 x 2 Supports clock frequencies up to 100 MHz Fast access times of 6.5ns Free-running CLKA and CLKB may be asynchronous or coincident (simultaneous reading and writing of data on a single clock edge is permitted) Two independent clocked FIFOs buffering data in opposite directions Mailbox bypass register for each FIFO Programmable Almost-Full and Almost-Empty flags Microprocessor Interface Control Logic FFA/IRA, EFA/ORA, AEA, and AFA flags synchronized by CLKA FFB/IRB, EFB/ORB, AEB, and AFB flags synchronized by CLKB
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Select IDT Standard timing (using EFA, EFB, FFA and FFB flags functions) or First Word Fall Through timing (using ORA, ORB, IRA and IRB flag functions) Available in 132-pin Plastic Quad Flatpack (PQFP) or space-saving 120-pin Thin Quad Flatpack (TQFP) Functionally compatible to the 5V operating IDT723622/723632/ 723642 Industrial temperature range (–40οC to +85οC) is available
DESCRIPTION:
The IDT72V3622/72V3632/72V3642 are functionally compatible versions of the IDT723622/723632/723642, designed to run off a 3.3V supply for exceptionally low-power consumption. These devices are monolithic, highspeed, low-power, CMOS Bidirectional SyncFIFO (clocked) memories which support clock frequencies up to 100MHz and have read access times as fast as 6.5ns. Two independent 256/512/1,024 x 36 dual-port SRAM FIFOs on board each chip buffer data in opposite directions. Communication between
.UNCTIONAL BLOCK DIAGRAM
CLKA CSA W/RA ENA MBA Mail 1 Register Input Register RAM ARRAY 256 x 36 512 x 36 1,024 x 36 Output Register Port-A Control Logic
MBF1
RST1
FIFO1, Mail1 Reset Logic
36
36
Write Pointer
Read Pointer EFB/ORB AEB
FFA/IRA AFA
FIFO 1
Status Flag Logic
FS0 FS1 A0 - A35
10
Programmable Flag Offset Registers
FIFO 2
Timing Mode
FWFT B0 - B35
EFA/ORA AEA
Status Flag Logic Write Pointer
36
FFB/IRB AFB
36
Read Pointer
RAM ARRAY 256 x 36 512 x 36 1,024 x 36 Mail 2 Register
Output Register
FIFO2, Mail2 Reset Logic Input Register
RST2
Port-B Control Logic
CLKB CSB W/RB ENB MBB
4660 drw 01
MBF2
IDT, the IDT logo are registered trademarks of Integrated Device Technology, Inc. SyncBiFIFO is a trademark of Integrated Device Technology, Inc.
COMMERCIAL TEMPERATURE RANGE
DECEMBER 2001
DSC-4660/4
1
2001 Integrated Device Technology, Inc. All rights reserved. Product specifications subject to change without notice.
IDT72V3622/72V3632/72V3642 CMOS 3.3V SyncBiFIFOTM 256 x 36 x 2, 512 x 36 x 2, 1,024 x 36 x 2
COMMERCIAL TEMPERATURE RANGE
DESCRIPTION (CONTINUED)
each port may bypass the FIFOs via two 36-bit mailbox registers. Each mailbox register has a flag to signal when new mail has been stored. These devices are a synchronous (clocked) FIFO, meaning each port employs a synchronous interface. All data transfers through a port are gated to the LOW-to-HIGH transition of a port clock by enable signals. The clocks for each port are independent of one another and can be asynchronous or coincident. The enables for each port are arranged to provide a simple bidirectional interface between microprocessors and/or buses with synchronous control. These devices have two modes of operation: In the IDT Standard mode, the first word written to an empty FIFO is deposited into the memory array. A read operation is required to access that word (along with all other words
residing in memory). In the First Word Fall Through mode (FWFT), the first long-word (36-bit wide) written to an empty FIFO appears automatically on the outputs, no read operation required (Nevertheless, accessing subsequent words does necessitate a formal read request). The state of the FWFT pin during FIFO operation determines the mode in use. Each FIFO has a combined Empty/Output Ready Flag (EFA/ORA and EFB/ORB) and a combined Full/Input Ready Flag (FFA/IRA and FFB/ IRB). The EF and FF functions are selected in the IDT Standard mode. EF indicates whether or not the FIFO memory is empty. FF shows whether the memory is full or not. The IR and OR functions are selected in the First Word Fall Through mode. IR indicates whether or not the FIFO has available memory locations. OR shows whether the FIFO has data available for reading or not. It marks the presence of valid data on the outputs.
PIN CON.IGURATION
NC NC VCC CLKB ENB W/RB CSB GND FFB/IRB EFB/ORB AFB AEB VCC MBF1 MBB RST2 FS1 GND FS0 RST1 MBA MBF2 AEA AFA VCC EFA/ORA FFA/IRA CSA W/RA ENA CLKA GND NC
NC B35 B34 B33 B32 GND B31 B30 B29 B28 B27 B26 VCC B25 B24 GND B23 B22 B21 B20 B19 B18 GND B17 B16 VCC B15 B14 B13 B12 GND NC NC 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 132 131 130 129 128 127 126 125 124 123 122 121 120 119 118 117
116 115 114 1.