Download Xilinx UG331 Spartan-3 Generation FPGA User Guide

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Table 15-1:
Introduction
Embedded Processing/Control Solutions for Spartan-3 Generation FPGAs (Continued)
Function/Feature
PicoBlaze Processor
MicroBlaze Processor
2
1 to 3, 34 for integer divide
31 locations (internal)
Variable size, in data memory
1, Expandable
1, Expandable
4 clock cycles
(46 ns at maximum clock rate)
7 to 40 clock cycles
(application dependent)
Instruction Cache
N/A
64 to 64K
Data Cache
N/A
64 to 64K
Floating-Point Unit
N/A
Optional, up to 120X performance
improvement
Hardware Multiplier
N/A
32x32 = 32 in 3 cycles
Hardware Divider
N/A
Optional, up to 20% performance
improvement
Hardware Barrel Shifter
N/A
Optional, up to 15X performance
improvement
Hardware Debugger Support
N/A
XMD
LocalLink Direct Processor
Interface
N/A
200 MB/sec communication
Clocks per Instruction
Call/Return/Interrupt Stack
Interrupts
Maximum Interrupt Latency
The PicoBlaze processor is always fully embedded within a Spartan-3 generation FPGA
using on-chip block RAM and distributed RAM for code and data storage. The MicroBlaze
processor optionally uses internal FPGA memory resources or interfaces to external
memory to support larger code or data storage requirements. The Embedded
Development Kit (EDK) for the MicroBlaze processor includes hardware IP cores to
support external Flash, SRAM, SDRAM, DDR DRAM, and ZBT SRAM memory. Similarly,
the MicroBlaze processor supports both instruction and data caches, each up to 64 Kbytes,
to increase performance when connected to external memory.
Table 15-2:
PicoBlaze and MicroBlaze Resource Requirements and Performance
Function/Feature
PicoBlaze Processor
MicroBlaze Processor
96
525
0.5 or 1
2+
From US$0.40
From US$1.40
Percent of XC3SD1800A
0.5% – 1%
3%+
Percent of XC3SD3400A
0.5% – 1%
2%+
17%-33%
75%+
Resource Requirements
Slices (4 slices = 1 CLB)
Block RAMs
Effective cost in high-volume
applications (250Ku)
Spartan-3A DSP FPGAs
Spartan-3A/3AN FPGAs
Percent of XC3S50A/AN
Spartan-3 Generation FPGA User Guide
UG331 (v1.5) January 21, 2009
www.xilinx.com
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