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| Author |
Message |
Mrinmoy Dey
Joined: 23 Jan 2018
Posts: 44
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| Bit Field Error in Data Structure |
 Posted: Thu Mar 30, 2023 5:30 am |
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Hi,
I am using PIC18F66K40 in one of my project to communicate with a peripheral
device and for register mapping of the peripheral I am using data structure with bit field.
| Code: |
typedef struct _ST_REG_0x01
{
unsigned int8 ADC_MODE : 2;
unsigned int8 CS_SEL : 2;
unsigned int8 CLK_SEL : 2;
unsigned int8 CONFIG0 : 2;
}ST_REG_0x01;
typedef union _UN_CONFIG0_REG_01h
{
ST_REG_0x01 m_ST_REG_0x01_bits;
unsigned int8 m_ui8Reg_0x1;
}UN_CONFIG0_REG_01h_t;
typedef struct _ST_REG_0x02
{
unsigned int8 Reserved : 2;
unsigned int8 OSR : 4;
unsigned int8 PRESCALER : 2;
}ST_REG_0x02;
typedef union _UN_CONFIG1_REG_02h
{
ST_REG_0x02 m_ST_REG_0x02_bits;
unsigned int8 m_ui8Reg_0x2;
}UN_CONFIG1_REG_02h_t;
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The first register data structure does not generate any error whereas the second one generates errors like :
Error#28 Expecting an identifier
Error#36 Expecting a ; or ,
Error#34 Unknown type
My compiler version is 5.101
I can't find out any possible wayout from the errors.
Anyone with any idea about that will be helpful. |
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Ttelmah
Joined: 11 Mar 2010
Posts: 19966
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| Posted: Thu Mar 30, 2023 6:29 am |
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As posted, both compile without errors for me, on your compiler version.
I'd suggest that possibly you have something else possibly defined, that
is causing the issue. So perhaps 'Reserved' is #defined somewhere, or
'PRESCALER'. The latter in particular might well be #defined in one of
the standard libraries.
If you are in the standard IDE, and this is happening, the item that is
causing this should be underlined in red when the compile fails. |
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Mrinmoy Dey
Joined: 23 Jan 2018
Posts: 44
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| Posted: Thu Mar 30, 2023 11:10 am |
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@Ttelmah
You are absolutely right; the Reserved member variable in the data structure was the problem and that may be #defined somewhere in the standard library with the exactly same spelling. Once I make it in caps the code is successfully compiled.
Thank you so much.  |
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Ttelmah
Joined: 11 Mar 2010
Posts: 19966
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| Posted: Fri Mar 31, 2023 1:54 am |
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Glad I got it.
Also shows though how to debug such a problem. I made a bare program
and tried your structures, which then worked. Gave an instant hint to what
was happening, so I then added a #define for 'Reserved', and immediately
the problem appeared. |
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