PDSP16318A

PDSP16318/16318A PDSP16318/PDSP16318A Complex Accumulator Advance Information Supersedes version DS3708 - 2.4 September 1996 DS3708 - 3.1 November 1998 The PDSP16318/A contains two independent 20-bit Adder/Subtractors combined with accumulator registers and shift structures. The four port architecture permits full 20MHz throughout in FFT and filter applications. Two PDSP16318As combined with a single PDSP16112A Complex Multiplier provide a complete arithmetic solution for a Radix 2 DIT FFT Butterfly. A new complex Butterfly result can be generated every 50ns allowing 1K complex FFTs to be executed in 256µs. GC100 FEATURES s s s s s s s s s s s s s s Full 20MHz Throughout in FFT Applications Four Independent 16-bit I/O Ports 20-bit Addition or Accumulation Fully Compatible with PDSP16112 Complex Multiplier On Chip Shift Structures for Result Scaling Overflow Detection Independent Three-State Outputs and Clock Enables for 2 Port 20MHz Operation 1.4 micron CMOS 500mW Maximum Power Dissipation 100 CQFP package Fig.1 Pin connections - Top view (GC100) ASSOCIATED PRODUCTS PDSP16112 PDSP16116 PDSP1601 PDSP16330 16 x 12 Complex Multiplier 16 x 16 Complex Multiplier ALU and Barrel Shifter Pythagoras Processor ORDERING INFORMATION Industrial (-40°C to +85°C) PDSP16318A/IG/GC1R (20MHz - QFP) Military (-55°C to +125°C) PDSP16318/MC/GC1R (10MHz - QFP MIL STD 883C Screened) N.B. Further details of the Military grade part are available in a separate datasheet APPLICATIONS High speed Complex FFT or DFTs Complex Finite Impulse Response (FIR) Filtering Complex Conjugation Complex Correlation/Convolution A REG DELAY B SHIFT A REG C A SHIFT B REG B REG D Fig. 2 PDSP16318 simplified block diagram 1 PDSP16318/16318A CEA DEL ASR S2:0 OEC 16 A A REG 16 8 CYCLE DELAY MUX 20 B 20 SHIFT A 16 REG 16 D 20 MUX REG 20 CLK 20 MS MUX 20 REG CLR OVR A 16 SHIFT 16 B REG 16 B 20 REG 16 D CEB ASI OED Fig. 3 Block diagram 2 PDSP16318/16318A FUNCTIONAL DESCRIPTION The PDSP16318 is a Dual 20-bit Adder/Subtractor configured to support Complex Arithmetic. The device may be used with each of the adders allocated to real or imaginary data (e.g. Complex Conjugation), the entire device allocated to Real or Imaginary Data (e.g. Radix 2 Butterflys) or each of the adders configured as accumulators and allocated to real or imaginary data (Complex Filters). Each of these modes ensures that a full 20MHz throughput is maintained through both adders, the first and last mode illustrating true Complex operation, where both real and imaginary data is handled by the single device. Both Adder/Subtractors may be controlled independently via the ASR and ASI inputs. These controls permit A + B, A - B, B - A or pass A operations, where the A input to the Adder is derived from the input multiplexer. The CLR control line allows the clearing of both accumulator registers. The two multiplexers may be controlled via the MS inputs, to select either new input data, or fed-back data from the accumulator registers. The PDSP16318 contains an 8cycle deskew register selected via the DEL control. This deskew register is used in FFT applications to ensure correct phasing of data that has not passed through the PDSP16112 Complex Multiplier. The 16-bit outputs from the PDSP16318 are derived from the 20-bit result generated by the Adders. The three bit S2:0 input selects eight different shifted output formats ranging from the most significant 16 bits of the 20-bit data, to the least significant 13 bits of the 20-bit data. In this mode the 14th, 15th and 16th bits of the output are set to zero. The shift selected is applied to both adder outputs, and determines the function of the OVR flag. The OVR flag becomes active when either of the two adders produces a result that has more significant digits than the MSB of the 16-bit output from the device. In this manner all cases when invalid data appears on the output are flagged. Symbol A15:0 B15:0 C15:0 D15:0 CLK CEA CEB OEC OED OVR Type Input Input Output Output Input Input Input Input Input Output Description Data presented to this input is loaded into the input register on the rising edge of CLK. A15 is the MSB. Data presented to this input is loaded into the input register on the rising edge of CLK. B15 is the MSB and has the same weighting as A15. New data appears on this output after the rising edge of CLK. C15 is the MSB. New data appears on this output after the rising edge of CLK. C15 is the MSB. Common Clock to all internal registers Clock enable: when low the clock to the A input register is enabled. Clock enable: when low the clock to the B input register is enabled. Output enable: Asynchronous 3-state output control: The C outputs are in a high impedance state when this input is high. Output enable: Asynchronous 3-state output control: The D outputs are in a high impedance state when this input is high. Overflow flag: This flag will go high in any cycle during which either the output data overflows the number range selected or either of the adder results overflow. A new OVR appears after the rising edge of the CLK. Add/subtract Real: Control input for the 'Real' adder. This input is latched by the rising edge of clock. Add/subtract Imag: Control input for the 'Imag' adder. This input is latched by the rising edge of clock. Accumulator Clear: Common accumulator clear for both Adder/Subtractor units. This input is latched by the rising edge of CLK. Mux select: Control input for both adder multiplexers. This input is latched by the rising edge of CLK. When high the feedback path is selected. Scaling control: This input selects the 16-bit field from the 20-bit adder result that is routed to the outputs. This input is latched by the rising edge of CLK. Delay Control: This input selects the delayed input to the real adder for operations involving the PDSP16112. This input is latched by the rising edge of CLK. +5V supply: Both Vcc pins must be connected. 0V supply: Both GND pins must be connected. ASR1:0 ASI1:0 CLR MS S2:0 DEL VCC GND Input Input Input Input Input Input Power Ground 3 PDSP16318/16318A GC pin Function GC pin 77 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 5 D7 D8 D9 D10 GND VCC D11 D12 D13 D14 D15 C15 C14 C13 C12 VCC GND C11 C10 C9 C8 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 Function GC pin C7 C6 C5 C4 C3 C2 C1 C0 OED OEC S2 S1 S0 MS ASI1 ASI0 DEL CLR ASR1 ASR0 A0 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 Function GC pin Function A1 A2 A3 A4 A5 A6 A7 A8 A9 A10 A11 A12 A13 A14 A15 CEA B15 B14 B13 B12 B11 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 B10 B9 B8 B7 B6 B5 B4 B3 B2 B1 B0 CLK CEB OVR D0 D1 D2 D3 D4 D5 D6 Device Pinout for ceramic QFP (GC100) ASR or ASI ASX1 ASX0 0 0 1 1 0 1 0 1 ALU Function A+B A A-B B-A DEL 0 1 Delay Mux Control A port input Delayed A port input MS 0 1 Real and Imag' Mux Control B port input/Del mux output C accumulator/D accumualtor S2:0 S2 0 0 0 0 1 1 1 1 S1 0 0 1 1 0 0 1 1 S0 0 1 0 1 0 1 0 1 19 15 18 14 15 17 13 14 15 16 12 13 14 15 15 11 12 13 14 15 14 10 11 12 13 14 15 13 9 10 11 12 13 14 15 12 8 9 10 11 12 13 14 15 11 7 8 9 10 11 12 13 14 Adder result 10 6 7 8 9 10 11 12 13 9 5 6 7 8 9 10 11 12 8 4 5 6 7 8 9 10 11 7 3 4 5 6 7 8 9 10 6 2 3 4 5 6 7 8 9 5 1 2 3 4 5 6 7 8 4 0 1 2 3 4 5 6 7 3 2 1 0 0 1 2 3 4 5 6 0 1 2 3 4 5 0 1 2 3 4 0 1 2 3 NOTE This table shows the portion of the adder result passed to the D15:0 and C15:0 outputs. Where fewer than 16 adder bits are selected the output data is padded with zeros. 4 PDSP16318/16318A ABSOLUTE MAXIMUM RATINGS (Note 1) Supply voltage VCC -0.5V to 7.0V Input voltage VIN -0.9V to VCC +0.9V Output voltage VOUT -0.9V to VCC +0.9V Clamp diode current per pin Ik (see Note 2) 18mA Static discharge voltage (HMB) VSTAT 500V Storage temperature range TS -65°C to +150°C Ambient temperature with power applied Tamb Industrial -40°C to +85°C Military -55°C to +125°C Junction temperature 150°C Package power dissipation PTOT 1000mW Test Waveform - measurement level Delay from output high to output high impedance VH 0.5V Delay from output low to output high impedance VL 0.5V Delay from output high impedance to Output low 1.5V 0.5V NOTES 1. Exceeding these ratings may cause permanent damage. Functional operation under these conditions is not implied. 2. Maximum dissipation or 1 second should not be exceeded, only one output to be tested at any one time. 3. Exposure to absolute maximum ratings for extended periods may affect device reliability. Delay from output high impedance to Output high 1.5V 0.5V NOTES 1. VH - Voltage reached when output driven high 2. VL - Voltage reached when output driven low THERMAL CHARACTERISTICS Package Type GC θJC °C/W 12 θJA °C/W 35 IOL DUT 1.5V 100p IOH 5 PDSP16318/16318A ELECTRICAL CHARACTERISTICS Test conditions (unless otherwise stated): Tamb (Commercial) = 0°C to +70°C, VCC = 5.0V ± 5%, GND = 0V Tamb (Industrial) =-40°C to +85°C, VCC = 5.0V ± 10%, GND = 0V Tamb (Military) =-55°C to +125°C, VCC = 5.0V ± 10%, GND = 0V STATIC CHARACTERISTICS Value Characteristic Symbol Min. Output high voltage Output low voltage Input high voltage Input low voltage Input leakage current Output leakage current Output SC current Input capacitance VOH VOL VIH VIL IIL loz IOS CIN 2.4 3.5 -10 -50 20 Typ. Max. 0.4 0.5 +10 +50 200 V V V V µA µA mA pF IOH = 3.2mA lOL=-3.2mA Units Conditions 9 GND < VIN