1 1999 integrated device technology, inc. dsc-4678/- ? july 1999 3.3 volt cmos syncfifo tm with bus-matching 2,048 x 36, 4,096 x 36, 8,192 x 36, 16,384 x 36, 32,768 x 36, 65,536 x 36 advance information idt72v3653 idt72v3663 idt72v3673 idt72v3683 idt72v3693 idt72v36103 features: ? memory storage capacity: idt72v3653C2,048 x 36 idt72v3663C4,096 x 36 idt72v3673C8,192 x 36 idt72v3683C16,384 x 36 idt72v3693C32,768 x 36 idt72v36103C65,536 x 36 ? clock frequencies up to 100 mhz (6.5 ns access time) ? clocked fifo buffering data from port a to port b ? idt standard timing (using ef ef ef ef ef and ff ff ff ff ff ) or first word fall through timing (using or and ir flag functions) ? programmable almost-empty and almost-full flags; each has five default offsets (8, 16, 64, 256 and 1,024) ? serial or parallel programming of partial flags ? port b bus sizing of 36 bits (long word), 18 bits (word) and 9 bits (byte) ? big- or little-endian format for word and byte bus sizes ? retransmit capability ? reset clears data and configures fifo, partial reset clears data but retains configuration settings ? mailbox bypass registers for each fifo ? free-running clka and clkb may be asynchronous or coincident (simultaneous reading and writing of data on a single clock edge is permitted) ? easily expandable in width and depth ? auto power down minimizes power dissipation ? available in a space-saving 128-pin thin quad flatpack (tqfp) ? pin and functionally compatible versions of the 5v operating idt723653/723663/723673 ? pin compatible with the lower density parts, idt72v3623/ 72v3633/72v3643 ? industrial temperature range (C40 c to +85 c) is available functional block diagram mail 1 register programmable flag offset registers status flag logic ef /or ae 36 ff /ir af 36 timing mode fwft a 0 -a 35 fs2 fs0/sd fs1/ sen b 0 -b 35 write pointer read pointer mail 2 register mbf2 clkb csb w /rb enb mbb be bm size port-b control logic 9 4678 drw 01 input register ram array 2,048 x 36 4,096 x 36 8,192 x 36 16,384 x 36 32,768 x 36 65,536 x 36 clka csa w/ ra ena mba port-a control logic fifo1 mail1, mail2, reset logic rs1 mbf1 36 bus- matching output register prs 36 36 rs2 36 fifo retransmit logic rt rtm
2 commercial temperature range idt72v3653/72v3663/72v3673/72v3683/72v3693/72v36103 100 mhz and has read access times as fast as 6.5 ns. the 2,048/4,096/8,192/ 16,384/32,768/65,536 x 36 dual-port sram fifo buffers data from port a to port b. fifo data on port b can output in 36-bit, 18-bit, or 9-bit formats with a choice of big- or little-endian configurations. these devices are synchronous (clocked) fifos, meaning each port employs a synchronous interface. all data transfers through a port are gated description: the idt72v3653/72v3663/72v3673/72v3683/72v3693/72v36103 are pin and functionally compatible versions of the idt723653/723663/723673, designed to run off a 3.3v supply for exceptionally low power consumption. these devices are monolithic, high-speed, low-power, cmos unidirectional synchronous (clocked) fifo memory which supports clock frequencies up to pin configuration tqfp (pk128-1, order code: pf) top view w/ ra clkb 4678 drw 02 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 ena clka gnd a35 a34 a33 a32 vcc a31 a30 gnd a29 a28 a27 a26 a25 a24 a23 be/ fwft gnd a22 vcc a21 a20 a19 a18 gnd a17 a16 a15 a14 a13 vcc a12 gnd a11 a10 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 102 101 128 127 126 125 124 123 122 121 120 119 118 117 116 115 114 113 112 111 110 109 108 107 106 105 vcc vcc b35 b34 b33 b32 rtm gnd b31 b30 b29 b28 b27 b26 vcc b25 b24 bm gnd b23 b22 b21 b20 b19 b18 gnd b17 b16 vcc b15 b14 b13 b12 gnd b11 b10 csa ff /ir nc prs / rt vcc af nc mbf2 mba rs1 fs0/sd gnd gnd fs1/ sen rs2 mbb mbf1 vcc ae nc ef /or nc gnd csb w /rb enb a9 a8 a7 a6 gnd a5 a4 a3 vcc a2 a1 a0 gnd b0 b1 b2 b3 b4 b5 gnd b6 vcc b7 b8 b9 104 103 index size fs2
3 idt72v3653/72v3663/72v3673/72v3683/72v3693/72v36103 commercial temperature range 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 synchro- nous control. communication between each port may bypass the fifo via two mailbox registers. the mailbox registers' width matches the selected port b bus width. each mailbox register has a flag ( mbf1 and mbf2 ) to signal when new mail has been stored. two kinds of reset are available on these fifos: reset and partial reset. reset initializes the read and write pointers to the first location of the memory array and selects serial flag programming, parallel flag programming, or one of five possible default flag offset settings, 8, 16, 64, 256 or 1,024. partial reset also sets the read and write pointers to the first location of the memory. unlike reset, any settings existing prior to partial reset (i.e., programming method and partial flag default offsets) are retained. partial reset is useful since it permits flushing of the fifo memory without changing any configuration settings. the fifo has retransmit capability, a retransmit is performed after four clock cycles of clka and clkb, by takingthe retransmit pin, rt low while the retransmit mode pin, rtm is high. when a retransmit is performed the read pointer is reset to the first memory location. 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 word written to an empty fifo appears automatically on the outputs, no read operation required (nevertheless, accessing subsequent words does neces- sitate a formal read request). the state of the be/ fwft pin during reset determines the mode in use. the fifo has a combined empty/output ready flag ( ef /or ) and a combined full/input ready flag ( ff /ir). 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. the fifo has a programmable almost-empty flag ( ae ) and a program- mable almost-full flag ( af ). ae indicates when a selected number of words remain in the fifo memory. af indicates when the fifo contains more than a selected number of words. ff /ir and af are two-stage synchronized to the port clock that writes data into its array. ef /or and ae are two-stage synchronized to the port clock that reads data from its array. programmable offsets for ae and af are loaded in parallel using port a or in serial via the sd input. five default offset settings are also provided. the ae threshold can be set at 8, 16, 64, 256 or 1,024 locations from the empty boundary and the af threshold can be set at 8, 16, 64, 256 or 1,024 locations from the full boundary. all these choices are made using the fs0, fs1 and fs2 inputs during reset. interspersed parity is available and can be selected during a master reset of the fifo. if interspersed parity is selected then during parallel programming of the flag offset values, the device will ignore data lines a8, a17, a26 and a35. if non-interspersed parity is selected then data lines a32, a33, a34 and a35 will be ignored, (a8, a17 and a26 will become valid bits). two or more devices may be used in parallel to create wider data paths. in first word fall through mode, more than one device may be connected in series to create greater word depths. the addition of external components is unnecessary. if, at any time, the fifo is not actively performing a function, the chip will automatically power down. during the power down state, supply current consumption (i cc ) is at a minimum. initiating any operation (by activating control inputs) will immediately take the device out of the power down state. the idt72v3653/72v3663/72v3673/72v3683/72v3693/72v36103 are characterized for operation from 0 c to 70 c. industrial temperature range (-40 o c to +85 o c) is available by special order. they are fabricated using idts high speed, submicron cmos technology.
4 commercial temperature range idt72v3653/72v3663/72v3673/72v3683/72v3693/72v36103 pin descriptions symbol name i/o description a0-a35 port a data i/o 36-bit bidirectional data port for side a. ae almost-empty flag o programmable almost-empty flag synchronized to clkb. it is low when the number of words in (port b) the fifo is less than or equal to the value in the almost-empty b offset register, x. af almost-full flag o programmable almost-full flag synchronized to clka. it is low when the number of empty (port a) locations in the fifo is less than or equal to the value in the almost-full a offset register, y. b0-b35 port b data i/o 36-bit bidirectional data port for side b. be/ fwft big-endian/ i this is a dual purpose pin. during master reset, a high on be will select big-endian operation. first word in this case, depending on the bus size, the most significant byte or word written to port a is read fall through from port b first. a low on be will select little-endian operation. in this case, the least significant byte or word written to port a is read from port b first. after master reset, this pin selects the timing mode. a high on fwft selects idt standard mode, a low selects first word fall through mode. once the timing mode has been selected, the level on fwft must be static throughout device operation. bm bus-match select i a high on this pin enables either byte or word bus width on port b, depending on the state of (port b) size. a low selects long word operation. bm works with size and be to select the bus size and endian arrangement for port b. the level of bm must be static throughout device operation. clka port a clock i clka is a continuous clock that synchronizes all data transfers through port a and can be asynchronous or coincident to clkb. ff /ir and af are synchronized to the low-to-high transition of clka. clkb port b clock i clkb is a continuous clock that synchronizes all data transfers through port b and can be asynchronous or coincident to clka. ef /or and ae are synchronized to the low-to-high transition of clkb. csa port a chip i csa must be low to enable to low-to-high transition of clka to read or write on port a. the select a0-a35 outputs are in the high-impedance state when csa is high. csb port b chip i csb must be low to enable a low-to-high transition of clkb to read or write data on port b. select the b0-b35 outputs are in the high-impedance state when csb is high. ef /or empty/output o this is a dual function pin. in the idt standard mode, the ef function is selected. ef indicates ready flag whether or not the fifo memory is empty. in the fwft mode, the or function is selected. or indicates (port b) the presence of valid data on the b0-b35 outputs, available for reading. ef /or is synchronized to the low-to-high transition of clkb. ena port a enable i ena must be high to enable a low-to-high transition of clka to read or write data on port a. enb port b enable i enb must be high to enable a low-to-high transition of clkb to read or write data on port b. ff /ir full/input o this is a dual function pin. in the idt standard mode, the ff function is selected. ff indicates ready flag whether or not the fifo memory is full. in the fwft mode, the ir function is selected. ir (port a) indicates whether or not there is space available for writing to the fifo memory. ff /ir is synchronized to the low-to-high transition of clka. fs0/sd flag offset select 0/ i fs1/ sen and fs0/sd are dual-purpose inputs used for flag offset register programming. during 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 fs2 flag offset select 2 edge on 2 clka load the bit present on fs0/sd into the x and y registers. the number of bit writes required to program the offset registers is 22 for the 72v3653, 24 for the 72v3663, 26 for the 72v3673, 28 for the 72v3683, 30 for the 72v3693 and, 32 for the 72v36103. the first bit write stores the y-register msb and the last bit write stores the x-register lsb.
5 idt72v3653/72v3663/72v3673/72v3683/72v3693/72v36103 commercial temperature range symbol name i/o description pin descriptions (continued) mba port a mailbox i a high level on mba chooses a mailbox register for a port a read or write operation. select mbb port b mailbox i a high level on mbb chooses a mailbox register for a port b read or write operation. when the select b0-b35 outputs are active, a high level on mbb selects data from the mail1 register for output and a low level selects fifo data for output. mbf1 mail1 register flag o mbf1 is set low by a low-to-high transition of clka that writes data to the mail1 register. writes to the mail1 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 reset ( rs1 ) or partial reset ( prs ). mbf2 mail2 register flag o mbf2 is set low by a low-to-high transition of clkb that writes data to the mail2 register. writes to the mail2 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 reset ( rs2 ) or partial reset ( prs ). rs1 , rs2 resets i a low on both pins initializes the fifo read and write pointers to the first location of memory and sets the port b output register to all zeroes. a low-to-high transition on rs1 selects the programming method (serial or parallel) and one of five programmable flag default offsets. 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 rs1 is low. prs / partial reset/ i this pin muxed for both partial reset and retransmit operations, it is used in conjunction with the rtm rt retransmit pin.if rtm is low, then a low on this pin initializes the fifo 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 se lected bus size, endian arrangement, programming method (serial or parallel), and programmable flag settings are all retained. if rtm is high, then a low on this pin performs a retransmit and initializes the read pointer only, to the first memory location. rtm retransmit mode i this pin is used in conjunction with the rt pin. when rtm is high a retransmit is performed when rt is taken high. size 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 (port b) 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.
6 corporate headquarters for sales: for tech support: 2975 stender way 800-345-7015 or 408-727-6116 408-330-1753 santa clara, ca 95054 fax: 408-492-8674 fifohelp@idt.com www.idt.com pf pkg: www.idt.com/docs/psc4045.pdf the syncfifo is a trademark and the idt logo is a registered trademark of integrated device technology, inc. ordering information blank pf 10 15 20 l 72v3653 72v3663 72v3673 72v3683 72v3693 72v36103 4678 drw 23 commercial (0 o c to +70 o c) thin quad flat pack (tqfp, pk128-1) low power 2,048 x 36 ? 3.3v syncfifo with bus-matching 4,096 x 36 ? 3.3v syncfifo with bus-matching 8,192 x 36 ? 3.3v syncfifo with bus-matching 16,384 x 36 ? 3.3v syncfifo with bus-matching 32,768 x 36 ? 3.3v syncfifo with bus-matching 65,536 x 36 ? 3.3v syncfifo with bus-matching xxxxxx idt device type xxx x x power speed package process/ temperature range commercial only clock cycle time (t clk ) speed in nanoseconds note: 1. industrial temperature range is available by special order.
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