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Cant write port output with str912 demo board

Hi, I am new to ARM (usually work with 8051), and am working on a little RS232 GPIO board. Project is a serial input on port 3 (uart 1) takes 3 bytes in and writes the values to ports 0-2, and 4-9.

The program seems to be working fine on ports 4,7,8 and 9. On the other ports the direction registers seem to be stuck as inputs. in my main routine I have lines to configure all the ports as outputs:

SCU->GPIOOUT[0] = 0x5555; GPIO0->DDR = 0xFF; "" "" SCU->GPIOOUT[9] = 0x5555; GPIO9->DDR = 0xFF;

When I stop the program and look at the output registers the GPIO_DIR[x] registers stay at 0x00 on ports 0,1,2,3 5 and 6.

I tried single step through my startup configuration
code and the direction registers never change. Is there something I am missing for using these
ports as outputs?

Thanks,
Andrew

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  • Just an update:

    I made sure the GPIO ports were getting clocked in the startup file:

    CLOCK_SETUP     EQU     1
    SCU_CLKCNTR_Val EQU     0x00020000
    SCU_PLLCONF_Val EQU     0x000BC019
    SCU_PCGR0_Val   EQU     0x000004FB
    SCU_PCGR1_Val   EQU     0x00FFC00B
    

    the PCGR1 register is set to 0x00FFC00B, so all the IO ports and the uart0 should be getting clocked. Im really stuck here as to why its not working unless there is some other register I am missing. Like I said I am new to ARM, so I would appreciate any input.

    Thanks,
    Andrew

Reply
  • Just an update:

    I made sure the GPIO ports were getting clocked in the startup file:

    CLOCK_SETUP     EQU     1
    SCU_CLKCNTR_Val EQU     0x00020000
    SCU_PLLCONF_Val EQU     0x000BC019
    SCU_PCGR0_Val   EQU     0x000004FB
    SCU_PCGR1_Val   EQU     0x00FFC00B
    

    the PCGR1 register is set to 0x00FFC00B, so all the IO ports and the uart0 should be getting clocked. Im really stuck here as to why its not working unless there is some other register I am missing. Like I said I am new to ARM, so I would appreciate any input.

    Thanks,
    Andrew

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