Xilinx UG129 manual Instruction Set Simulation with pBlazIDE

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Chapter 12: Simulating PicoBlaze Code

Table 12-1:PicoBlaze Code Simulation Options

Verification Tool		Strengths	Weaknesses
Xilinx System	•	Full PicoBlaze system-level simulation	• Primarily only useful is already using
Generator		with the System Generator environment	Xilinx System Generator
	• Cycle-accurate Instruction Set
		Simulation (ISS)
	•	Single-step
	•	Breakpoints
	• Register and memory viewer
In-system on FPGA	•	Fast, real-time performance	• Poor visibility of register contents
	• Ideal for complex interactions
	• Integrated with peripherals, displays,
		UARTs, etc.

Furthermore, the pBlazIDE ISS offers full single-step and breakpoint support while viewing the PicoBlaze assembly source code. Evaluate the software timing for end application. Observe code coverage. Simulate basic FPGA interaction using the pBlazIDE DSIN, DSOUT, and DSIO directives (see “Defining I/O Ports (pBlazIDE),” page 76 for more information).

Best of all, the pBlazIDE graphical development environment is free! Download the latest version directly from the Mediatronix website:

http://www.mediatronix.com/pBlazeIDE.htm

The pBlazIDE ISS does not support full simulation of the PicoBlaze microcontroller embedded with all the other FPGA logic. Fortunately, the PicoBlaze core source files support both VHDL and Verilog simulation using the ModelSim simulator. ModelSim allows the entire design to be simulated, including accurate timing information and textual disassembly features.

If using the Xilinx System Generator software, there is full development and system-level simulation support for the PicoBlaze microcontroller. Refer to “Designing PicoBlaze Microcontroller Application” in the Xilinx System Generator User Guide (see Reference 3) for more information.

Instruction Set Simulation with pBlazIDE

The Mediatronix pBlazIDE instruction set simulator (ISS), shown in Figure 12-1, provides complete internal observability during code development. Begin simulation by clicking Assemble, as shown in Table 12-2. The pBlazIDE ISS also provides instruction breakpoints, single-stepping, register and RAM observation, code coverage, and software timing.

82	www.xilinx.com	PicoBlaze 8-bit Embedded Microcontroller
		UG129 (v1.1.2) June 24, 2008