topic Re: CF52235: UART in ColdFire/68K Microcontrollers and Processors

CF52235: UART

UDP — Mon, 07 Aug 2006 15:47:02 GMT

Hello

I am trying the work with the receive interrupt of the uart.

I succeeded to get an interrupt when sending data(byte) to the CF52235.

When i read the URBn register i get fault data.

my initialization of the Uart regs are:

Code:

#define UART_INT_LEVEL(x) ((byte)(x<<3)) #define UART_INT_PR_LEVEL(x) (x)MCF_UART0_UCR=0x10;//Reset Reciver And TransmitterMCF_UART0_UIMR=0x2;//Interrupt when Receive Is ReadyMCF_GPIO_PUAPAR=0x55;//Set To Primary Function (To Uart)/* UART 0 Mode Registers */MCF_UART0_UMR = 0x13;//No Parity ,8 Bits (UMR10)//UMR20 -->After UMR10 It Poits To UMR20MCF_UART0_UMR = 0x7;//1 Stop Bit Normal Mode (UMR20) Must Be After UMR10MCF_UART0_UCSR=0xDD;//Clock Source (f(sys)/2)//19200 Baud Rate--> Divider =~49MCF_UART0_UBG1=0x0;//MSB DividerMCF_UART0_UBG2=0x28;//LSB DividerMCF_UART0_UCR=0x5;//Enable Transmit&Receive//Enable Interrupt Of Uart (Not The MaskAll)MCF_INTC0_IMRL&=ENABLE_UART1_INT;MCF_INTC0_ICR13=UART_INT_LEVEL(6)|UART_INT_PR_LEVEL(2);

I read the data from the MCF_UART0_URB register ( (*(vuint8 *)(&__IPSBAR[0x00020C])) )

Why is that?

I also did't understand how the fifo works. How i read the fifo data ? what is the fifo address (i know the URB reg)?

Thanks

Alban formatted code & gave meaningful title

Message Edited by Alban on 2006-08-07 09:55 AM

Re: CF52235: UART

mjbcswitzerland — Tue, 08 Aug 2006 04:47:49 GMT

Hi UDP

I won't try to answer all question but did see some things when comparing my code, which may help:

1. To reset the receiver and transmitter you need to write 0x20 then 0x30 to UCR. 0x10 resets the command pointer only.

2. I use 0x0061 for 19600 (with 60MHz clock) - also UCSR = 0xdd. Divide Value = BUS_CLOCK/19200/32
Are you using 30MHz clock? 49 == 0x31 and not 0x28..

3. I think that this line is possibly faulty. MCF_INTC0_IMRL&=ENABLE_UART1_INT;
I think the bit should be inverted...? Maybe your define is already inverted though (?)

Hope it helps

Regards

Mark Butcher
www.mjbc.ch

Re: CF52235: UART

UDP — Tue, 08 Aug 2006 21:49:43 GMT

Thanks for the help

The problem was wrong CPU bus frequency.