QUESTION YAMON's uart3 of au1100

QUESTION YAMON's uart3 of au1100

[Nyauyama]

Hello!

I have a question about initialization of YAMON's uart3 of au1100.
BFC00000(BOOTLOC) is read by processing delay3.
Why BFC00000?


#define BOOTLOC (*(volatile unsigned int *)0xbfc00000)
int delay3(int n)
{
int i, j, v;
for( i = 0; i < n; ++i )
{
for( j = 0; j < 1000; ++j )
v += BOOTLOC;
}
return v;
}
void init_uart3()
{
uart3.uart_module_control = UART_CE; // disable the module, enable the
clocks
delay3(100); // 100 ms delay
uart3.uart_module_control = UART_CE | UART_ME; // enable the module
delay3(100); // delay another 100 ms
uart3.uart_interrupt_enable = 0; // disable interrupts
uart3.uart_fifo_control = UART_TR | UART_RR; // reset the receiver and
transmitter
uart3.uart_line_control = UART_WORD_8 | UART_NO_PARITY | UART_STOP_1;
uart3.uart_clock_divider = 156;
setbrg3(396000000,2); // set baud rate for default cpu clock
delay3(100);
}

Regards,
Nyauyama.

Re: QUESTION YAMON's uart3 of au1100

[Pete Popov]

Nyauyama wrote:
> Hello!
> 
> I have a question about initialization of YAMON's uart3 of au1100.
> BFC00000(BOOTLOC) is read by processing delay3.
> Why BFC00000?

Looks like just an arbitrary ad-hoc delay routine (delay3) that
reads from uncached space and throws away the value (just a delay).

What's the problem you're having?

Pete

> 
> 
> #define BOOTLOC (*(volatile unsigned int *)0xbfc00000)
> int delay3(int n)
> {
> int i, j, v;
> for( i = 0; i < n; ++i )
> {
> for( j = 0; j < 1000; ++j )
> v += BOOTLOC;
> }
> return v;
> }
> void init_uart3()
> {
> uart3.uart_module_control = UART_CE; // disable the module, enable the
> clocks
> delay3(100); // 100 ms delay
> uart3.uart_module_control = UART_CE | UART_ME; // enable the module
> delay3(100); // delay another 100 ms
> uart3.uart_interrupt_enable = 0; // disable interrupts
> uart3.uart_fifo_control = UART_TR | UART_RR; // reset the receiver and
> transmitter
> uart3.uart_line_control = UART_WORD_8 | UART_NO_PARITY | UART_STOP_1;
> uart3.uart_clock_divider = 156;
> setbrg3(396000000,2); // set baud rate for default cpu clock
> delay3(100);
> }
> 
> Regards,
> Nyauyama.
> 
> 
> 

Re: QUESTION YAMON's uart3 of au1100

[Nyauyama]

Pete Popov wrote:

>Nyauyama wrote:
>  
>
>>Hello!
>>
>>I have a question about initialization of YAMON's uart3 of au1100.
>>BFC00000(BOOTLOC) is read by processing delay3.
>>Why BFC00000?
>>    
>>
>
>Looks like just an arbitrary ad-hoc delay routine (delay3) that
>reads from uncached space and throws away the value (just a delay).
>
>What's the problem you're having?
>
>  Pete
>
>  
>
The problem occurs by UART3 after using uboot and starting Linux kernel.
Linux kernel has initialized UART3.
When the noise is received when uboot processes it,
anything cannot be received from uart3.
When having seen referring to the initialization of YAMON,
I have not understood the reason to read BFC00000.

Thank you for the reply.

Nyauyama