Motorola 24-Bit Digital Signal Processor, DSP56000 manual Using the OnCE, Begin Debug Activity

DSP56K TARGET SITE DEBUG SYSTEM REQUIREMENTS

10.10 DSP56K TARGET SITE DEBUG SYSTEM REQUIREMENTS

A typical DSP56K debug environment consists of a target system where the DSP56K re- sides in the user defined hardware. The debug serial port interfaces to the external com- mand controller over a 6-wire link which includes the 4 OnCE wires, a ground, and a reset wire. The reset wire is optional and is only used to reset the DSP56K and its associated circuitry.

The external command controller acts as the medium between the DSP56K target system and a host computer. The external command controller circuit acts as a DSP56K serial debug port driver and host computer command interpreter. The controller issues com- mands based on the host computer inputs from a user interface program which commu- nicates with the user.

10.11 USING THE OnCE

The following notations are used:

ACK = Wait for acknowledge on the DSO pin

CLK = Issue 24 clocks to read out data from the selected register

10.11.1 Begin Debug Activity

Most of the debug activities have the following beginning:

1.ACK

2.Save pipeline information:

a.Send command READ PDB REGISTER (10001001)

b.ACK

c.CLK

d.Send command READ PIL REGISTER (10001011)

e.ACK

f.CLK

3.Read PAB FIFO and fetch/decode info (this step is optional):

a.Send command READ PAB address for fetch (10001010)

b.ACK

c.CLK

d.Send command READ PAB address for decode (10010011)

e.ACK

MOTOROLA ON-CHIP EMULATION (OnCE) 10 - 21