TM 3.3 VOLT CMOS SyncFIFO 512 x 36 72V3631 1,024 x 36 72V3641 Available in space-saving 120-pin thin quad flat package (TQFP) FEATURES Pin and functionally compatible versions of the 5V operating Storage capacity: 723631/723641 72V3631 - 512 x 36 Easily expandable in width and depth 72V3641 - 1,024 x 36 Green parts are available, see ordering information Supports clock frequencies up to 67 MHz Fast access times of 10ns DESCRIPTION Free-running CLKA and CLKB can be asynchronous or coinci- dent (permits simultaneous reading and writing of data on a The 72V3631/72V3641 are pin and functionally compatible versons of the single clock edge) 723631/723641, designed to run off a 3.3V supply for exceptionally low-power Clocked FIFO buffering data from Port A to Port B consumption. These devices are monolithic high-speed, low-power, CMOS Synchronous read retransmit capability clocked FIFO memory. It supports clock frequencies up to 67 MHz and has read Mailbox register in each direction access times as fast as 10ns. The 512/1,024 x 36 dual-port SRAM FIFO buffers Programmable Almost-Full and Almost-Empty flags data from port A to Port B. The FIFO memory has retransmit capability, which Microprocessor interface control logic allows previously read data to be accessed again. The FIFO operates in First Input Ready (IR) and Almost-Full (AF) flags synchronized by Word Fall Through mode and has flags to indicate empty and full conditions and CLKA conditions and two programmable flags (Almost-Full and Almost-Empty) to Output Ready (OR) and Almost-Empty (AE) flags synchronized indicate when a selected number of words is stored in memory. Communication by CLKB FUNCTIONAL BLOCK DIAGRAM MBF1 Mail 1 Register CLKA Port-A CSA W/RA Control ENA Logic RAM ARRAY 512 x 36 MBA 1,024 x 36 Reset RST Logic RTM 36 Read Write RFM Pointer Pointer A0 - A35 B0 - B35 Status Flag OR IR Logic AF AE Flag Offset FS0/SD Registers FS1/SE 10 N CLKB Port-B CSB Control W/RB Logic ENB Mail 2 MBB Register 4658 drw 01 MBF2 COMMERCIAL TEMPERATURE RANGE 11 Oct.29.21 Input Register Output Sync Register Retransmit Logic72V3631/72V3641 3.3V CMOS SYNCFIFO 512 x 36 and 1,024 x 36 COMMERCIAL TEMPERATURE RANGE provide a simple interface between microprocessors and/or buses with DESCRIPTION (CONTINUED) synchronous control. between each port may take place with two 36-bit mailbox registers. Each The Input Ready (IR) flag and Almost-Full (AF) flag of the FIFO are two-stage mailbox register has a flag to signal when new mail has been stored. Two or synchronized to CLKA. The Output Ready (OR) flag and Almost-Empty (AE) more devices may be used in parallel to create wider data paths. Expansion flag of the FIFO are two-stage synchronized to CLKB. Offset values for the is also possible in word depth. Almost-Full and Almost-Empty flags of the FIFO can be programmed from port These devices are a clocked FIFO, which means each port employs a A or through a serial input. synchronous interface. All data transfers through a port are gated to the LOW- The 72V3631/72V3641 are characterized for operation from 0C to 70C. to-HIGH transition of a continuous (free-running) port clock by enable signals. These devices are fabricated using high speed, submicron CMOS technology. The continuous clocks for each port are independent of one another and can be asynchronous or coincident. The enables for each port are arranged to PIN CONFIGURATION VCC 91 60 B11 92 CLKB B10 59 93 ENB B9 58 94 B8 W/RB 57 95 B7 CSB 56 96 VCC GND 55 B6 MBF1 97 54 GND 98 GND 53 B5 99 MBB 52 B4 100 NC 51 B3 101 VCC 50 B2 102 RFM 49 B1 103 RTM 48 72V3631 B0 104 FS1/SEN 47 GND 105 72V3641 FS0/SD 46 GND 106 GND 45 A0 107 RST 44 A1 108 MBA 43 A2 109 MBF2 42 VCC 110 VCC 41 A3 111 AE 40 A4 112 AF 39 A5 113 VCC 38 GND 114 OR 37 A6 115 IR 36 A7 116 CSA 35 A8 117 W/RA 34 A9 118 ENA 33 A10 119 CLKA 32 A11 120 GND 31 GND 4658 drw 03 TOP VIEW NOTE: 1. NC No internal connection. Package Type Package Code Order Code TQFP PNG120 PF 2 Oct.29.21 A35 1 90 B35 A34 2 B34 89 A33 3 B33 88 A32 4 87 B32 VCC 5 GND 86 A31 6 B31 85 A30 7 84 B30 GND 8 B29 83 A29 9 B28 82 A28 10 81 B27 A27 11 B26 80 A26 12 VCC 79 A25 13 78 B25 A24 14 B24 77 A23 15 76 GND GND 16 75 B23 A22 17 B22 74 VCC 18 73 B21 A21 19 72 B20 A20 20 B19 71 A19 21 70 B18 A18 22 GND 69 GND 23 B17 68 A17 24 67 B16 A16 25 VCC 66 A15 26 B15 65 A14 27 64 B14 A13 28 B13 63 VCC 29 B12 62 A12 30 61 GND