User guide

ManualsBrandsARM ManualsComputer HardwareVERSION 1.2

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The following piece of target application code, supplied in file

Install_directory\Examples\dcc\inchan.s, shows this in action:

AREA InChannel, CODE, READONLY

ENTRY

MOV r1,#3 ; Number of words to read

LDR r2, =indata ; Address to store data read

pollin

MRC p14,0,r0,c0,c0 ; Read control register

TST r0, #1

BEQ pollin ; If R bit clear then loop

read

MRC p14,0,r3,c1,c0 ; read word into r3

STR r3,[r2],#4 ; Store to memory and

; update pointer

SUBS r1,r1,#1 ; Update counter

BNE pollin ; Loop if more words to read

MOV r0, #0x18 ; Angel_SWIreason_ReportException

LDR r1, =0x20026 ; ADP_Stopped_ApplicationExit

SWI 0x123456 ; ARM semihosting SWI

AREA Storage, DATA, READWRITE

indata

DCB "Duffmessage#"

END

4. Create an input file on the host containing, for example, And goodbye!.

5. Assemble and link this code using the following commands:

armasm -g inchan.s

armlink inchan.o -o inchan.axf

You have created an executable image in a file called inchan. Your next steps depend on your choice of debugger.

You can load the image, enable comms channel viewing, and execute the image by using:

• armsd (for command-line operation)

• AXD.

Issuing commands

If you are issuing commands:

1. Load the image into armsd using the following command:

armsd -li -adp -port s=1 inchan.axf

If you view the area of memory indata, you see its initial random contents:

examine indata

2. Enable communication and open the input file, then execute the program:

ccin input

3. When execution completes, view memory again and you can see the input has been read in:

examine indata

Using AXD

If you are using AXD:

1. Enable channel viewing. See the description of the Control system view pop-up menu in chapter 5 of the AXD

and armsd Debuggers Guide.

2. Load the image created above into AXD.

3. Use the channel viewer in AXD. See the description of the Comms Channel processor view in chapter 5 of the

AXD and armsd Debuggers Guide

4. In the Send field of the Channel Viewer, type And goodbye!, and click the Send button. The Left to Send

counter should show the number of bytes stored for sending to the target.

Debug Communications Channel