Application: memory monitor using JDC module

AN4623

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DocID027178 Rev 1

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Application: memory monitor using JDC module

2.1

Overview

This application note describes how to use the JDC module to implement a memory

monitor. To do this, the application implemented uses JOUT_IPS register to get out the data

and the JOUT Flag of MSR register to synchronize the external tool.

2.2

Implementation

The memory monitored is a 10 elements buffer of 8 bits. The application transfers the

content of each element of the buffer into the JOUT_IPS register and waits for the tool read

the data. When the tool read the data, the JOUT_INT (JOUT interrupt) occurs. At this point

the application can put a new data into JOUT_IPS register.

Following the buffer used by application:

•

uint8_t *buffer[MAX_BUFFER];//Buffer containing the RAM variable address to monitor

•

uint32_t nbuffer = 0;//buffer index used to indicate the next element to send

The first step consists of enabling of the JOUT interrupt:

•

JDC.MCR.B.JOUT_IEN = 0x1; //Enable JOUT Interrupt

•

INT_IRQ_INIT(JDC_JOUT_INT, JDC_JOUT_INT_PRIORITY); //Set priority for JDC

JOUT interrupt

The second step consists of setting first time the JOT_IPS register to activate the process

monitor:

•

JDC.JOUT_IPS.R = *(buffer[nbuffer]);

The code below is the ISR (Interrupt Service Routine) executed each time the JOUT_INT

occurs:

void JDC_JOUT_ISR(void)

{

JDC.MSR.R = 0x1;//Clear JOUT interrupt flag;

nbuffer++;//Increase buffer index counter

if (nbuffer == MAX_BUFFER)//Check if buffer index counter reach the

MAX_BUFFER value

{

nbuffer = 0;//reset buffer index counter

}

JDC.JOUT_IPS.R = *(buffer[nbuffer]);//update JOUT register value

}