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From: "jeremy" <chienyul@home.com>
To: <ecos-discuss@sourceware.cygnus.com>
Subject: Re: [ECOS] HAL register write problem
Date: Tue, 23 Jan 2001 16:16:00 -0000	[thread overview]
Message-ID: <004201c0859b$46d0fba0$7c6509c0@viatech.com> (raw)

I got it done! All registers should cast like this:
        ((volatile cyg_uint8 *) (XXX + 0xXX))
        ((volatile cyg_uint8 *) (XXX + 0xXX))
        ((volatile cyg_uint8 *) (XXX + 0xXX))
        ((volatile cyg_uint16 *) (XXX + 0xXX))

I only parenthesized the 16 bit register, and that was the problem.
In original pid codes, all registers are 8-bits, so it ok if all defined
this way:
((volatile cyg_uint8 *) XXX + 0xXX)
...
Is it because of the alignment?

Anyway, I should have tried this earlier :-)
Thanks to all helped me!!

jeremy



jeremy wrote:
>
> My platform is Samsung KS32C50100, which operates in big-endian mode.
> I got some problem with writing to register using HAL_WRITE function.
> For example, in plf_stub.c where I put the UART initialization
function
> in,
> Here I write some initialize value to UART control registers,
>  HAL_WRITE_UINT8 (CYG_DEVICE_SERIAL_RS232_UART_UTXBUF, 0x0);
>  HAL_WRITE_UINT8 (CYG_DEVICE_SERIAL_RS232_UART_URXBUF, 0x0);
>  HAL_WRITE_UINT16(CYG_DEVICE_SERIAL_RS232_UART_UBRDIV, 0x280);
>
> The first two lines for writing 8-bits registers works fine. But the
> last line doesn't write
> anything into the 16-bits register. I defined that 16-bits register
> like this in the first part
> of the program:
> #define CYG_DEVICE_SERIAL_RS232_UART_UBRDIV \
>     ((volatile cyg_uint16 *) CYG_DEVICE_SERIAL_RS232_UART_BASE + 0x14)

>>At a guess, you were probably intending to write

>#define CYG_DEVICE_SERIAL_RS232_UART_UBRDIV \
    ((volatile cyg_uint16 *) (CYG_DEVICE_SERIAL_RS232_UART_BASE + 0x14))

>>because adding 0x14 to something cast to a pointer to a 16-bit type
will
>>increment it by 2*0x14=0x28 bytes.

>>Jifl
--
>>Red Hat, Rustat House, Clifton Road, Cambridge, UK. Tel: +44 (1223)
271062
>>Un cheval, pas du glue. Pas du cheval, beaucoup du glue. || Opinions



             reply	other threads:[~2001-01-23 16:16 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2001-01-23 16:16 jeremy [this message]
2001-01-24  7:18 ` Grant Edwards
  -- strict thread matches above, loose matches on Subject: below --
2001-01-18 14:07 jeremy
2001-01-18 15:11 ` Gary Thomas
2001-01-18 19:04 ` Jonathan Larmour
2001-01-19  8:33 ` Grant Edwards
2001-01-19 19:37   ` jeremy
2001-01-22  0:40     ` Jesper Skov

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