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USB and UART interrupts together, problem!

Milton Godinho

Hi,

I am trying to setup a system where I use interrupts for the USB communication and UART but I have a problem, I can't use both at the same time ... Both work properly separated, once I try to use both it doesn't work anymore. I think it has to deal with the interrupt priority, because I still have the USB interrupt working once it has a higher priority (0) then the UART (2).
Someone has an idea? Thanks.
This is the initialization of both of them:

UART:

...
SCU_APBPeriphClockConfig(__UART0, ENABLE);
SCU_APBPeriphReset(__UART0,DISABLE);

SetCNTR(0);
SetISTR(0);
SCU_AHBPeriphClockConfig(__USB48M,ENABLE);

// UART Module //
UART_InitStructure.UART_WordLength = UART_WordLength_8D;
UART_InitStructure.UART_StopBits = UART_StopBits_1;
UART_InitStructure.UART_Parity = UART_Parity_No ;
UART_InitStructure.UART_BaudRate = 115200;
UART_InitStructure.UART_HardwareFlowControl = UART_HardwareFlowControl_None;
UART_InitStructure.UART_Mode = UART_Mode_Tx_Rx;
UART_InitStructure.UART_FIFO = UART_FIFO_Disable;

UART_DeInit(UART0);
UART_Init(UART0, &UART_InitStructure);

UART_ITConfig(UART0, UART_IT_Receive, ENABLE);
VIC_Config(UART0_ITLine, VIC_IRQ, 2);
VIC_ITCmd(UART0_ITLine, ENABLE);
/* Enable the UART0: start sending the transmit FIFO content to the hyperterminal */
UART_Cmd(UART0, ENABLE);
UART_ITConfig(UART0, UART_IT_Receive, ENABLE);
UART_LoopBackConfig(UART0, DISABLE);


USB:

SCU_USBCLKConfig(SCU_USBCLK_EXT);
// Enable USB clock //
SCU_AHBPeriphClockConfig(__USB, ENABLE);
SCU_AHBPeriphReset(__USB, DISABLE);
// USB Initialization
/* Enable and configure the priority of the USB_LP IRQ Channel*/
VIC_DeInit();
VIC_Config(USBLP_ITLine, VIC_IRQ, 0);
VIC_ITCmd(USBLP_ITLine, ENABLE);

/* USB initialization */
wInterrupt_Mask = IMR_MSK;

SetCNTR(0x0003);
Token_Event = 0; /* Flags of each endpoint interrupt */
pInformation = &Device_Info;
pInformation->ControlState = 2;
pProperty = &Device_Property;
/* Initialize devices one by one */
pProperty->Init();

Parents Reply Children
  • 0 in reply to Tsuneo Chinzei

    Hi Tsuneo,

    I run the usb demo that you give us the link below on my KEIL MCBSTR9 board with uVision3
    www.st.com/.../um0290.zip

    I find some interesting things I don't understand.

    1. If I use the following IRQ program, I will get an error "USB Device Not Recognized" on PC side.
    My IRQ prorgam is as follows:

    VectorAddr      EQU    0xFFFFF030       ; VIC Vector Address Register
VectorAddrDaisy EQU    0xFC000030       ; Daisy VIC Vector Address Register


        AREA IRQ, CODE, READONLY
        ARM

        PRESERVE8
        ALIGN
        EXPORT  IRQHandler
IRQHandler
        SUB     LR, LR, #4              ; Update Link Register
        STMFD   SP!, {R0-R12, LR}       ; Save Workspace & LR to Stack
        LDR     R0, =VectorAddr
        LDR     R0, [R0]                ; Read the Routine Address
        LDR     LR, =IRQReturnAddress   ; Read the Return Address
        BX      R0                      ; Branch to the IRQ Handler
IRQReturnAddress

        LDMFD   SP!, {R0-R12, PC}^      ; Return to program


        END

    2. If I use the nested interrupt IRQ program below, the error "USB Device is not recognized" will disapear. Test the prorgam on the Hyperterminals on two PCs. The USB prorgam works properly. However, if I send the message continueouly on LABVIEW using USB virtual com port on one PC, I will receive truncated message on the hyperterminal of another PC using com port 1.

    VectorAddr      EQU    0xFFFFF030       ; VIC Vector Address Register
VectorAddrDaisy EQU    0xFC000030       ; Daisy VIC Vector Address Register


        AREA IRQ, CODE, READONLY
        ARM

        PRESERVE8
        ALIGN
        EXPORT  IRQHandler

IRQHandler
        SUB     LR, LR, #4              ; Update Link Register
        STMFD   SP!, {R0-R12, LR}       ; Save Workspace & LR to Stack
        MRS     R0, SPSR                ; Copy SPSR to R0
        STMFD   SP!, {R0, R1}           ; Save SPSR to Stack (8-byte)
        LDR     R0, =VectorAddr
        LDR     R0, [R0]                ; Read the Routine Address
        LDR     R1, =VectorAddrDaisy
        LDR     R1, [R1]
        ; Padding between the acknowledge and re-enable of interrupts
        ; For more details, please refer to the following URL
        ; www.arm.com/.../3682.html
        NOP
        NOP
        MSR     CPSR_c, #0x1F           ; Switch to SYS Mode and enable IRQ
        STMFD   SP!, {R0, LR}           ; Save Link Register (8-byte Stack)
        LDR     LR, =IRQReturnAddress   ; Read the Return Address
        BX      R0                      ; Branch to the IRQ Handler
IRQReturnAddress
        LDMFD   SP!, {R0, LR}           ; Restore Link Register (8-byte Stack)
        MSR     CPSR_c, #0xD2           ; Switch to IRQ Mode
        LDR     R0, =VectorAddr         ; Write to the VectorAddress to clear
        STR     R0, [R0]                ; the respective Interrupt
        LDR     R1, =VectorAddrDaisy    ; Write to the VectorAddressDaisy to
        STR     R1, [R1]                ; clear the respective Interrupt
        LDMFD   SP!, {R0, R1}           ; Restore SPSR to R0
        MSR     SPSR_cxsf, R0           ; Restore SPSR
        LDMFD   SP!, {R0-R12, PC}^      ; Return to program


        END

    My questions are
    1. when PC will show "USB Device not Recognized"?
    2. why I will get truncated message?

    Thank you very much for your help.

    Lillian