Detailed Description

Atomic bit-field access macros for PIC24/dsPIC.

Initially, the code was taken from the article by Alex Borisov (russian), and modified a bit.

The kernel would not probably provide that kind of functionality, but the kernel itself needs it, so, it is made public so that application can use it too.

Definition in file tn_arch_pic24_bfa.h.

Go to the source code of this file.

Macros
#define	TN_BFA_SET 0x1111
	Command for `TN_BFA()` macro: Set bits in the bit field by mask; `...` macro param should be set to the bit mask to set. More...

#define	TN_BFA_CLR 0x2222
	Command for `TN_BFA()` macro: Clear bits in the bit field by mask; `...` macro param should be set to the bit mask to clear. More...

#define	TN_BFA_INV 0x3333
	Command for `TN_BFA()` macro: Invert bits in the bit field by mask; `...` macro param should be set to the bit mask to invert. More...

#define	TN_BFA_WR 0xAAAA
	Command for `TN_BFA()` macro: Write bit field; `...` macro param should be set to the value to write. More...

#define	TN_BFA_RD 0xBBBB
	Command for `TN_BFA()` macro: Read bit field; `...` macro param ignored. More...

#define	TN_BFA(comm, reg_name, field_name,...)
	Macro for atomic access to the structure bit field. More...

#define	TN_BFAR(comm, reg_name, lower, upper,...)
	Macro for atomic access to the structure bit field specified as a range. More...

Macro Definition Documentation

#define TN_BFA_SET 0x1111

Command for TN_BFA() macro: Set bits in the bit field by mask; ... macro param should be set to the bit mask to set.

Definition at line 76 of file tn_arch_pic24_bfa.h.

#define TN_BFA_CLR 0x2222

Command for TN_BFA() macro: Clear bits in the bit field by mask; ... macro param should be set to the bit mask to clear.

Definition at line 80 of file tn_arch_pic24_bfa.h.

#define TN_BFA_INV 0x3333

Command for TN_BFA() macro: Invert bits in the bit field by mask; ... macro param should be set to the bit mask to invert.

Definition at line 84 of file tn_arch_pic24_bfa.h.

#define TN_BFA_WR 0xAAAA

Command for TN_BFA() macro: Write bit field; ... macro param should be set to the value to write.

Definition at line 88 of file tn_arch_pic24_bfa.h.

#define TN_BFA_RD 0xBBBB

Command for TN_BFA() macro: Read bit field; ... macro param ignored.

Definition at line 92 of file tn_arch_pic24_bfa.h.

#define TN_BFA	(	comm,
		reg_name,
		field_name,
		...
	)

Macro for atomic access to the structure bit field.

The BFA acronym means Bit Field Access.

Parameters

comm	command to execute: `TN_BFA_WR` - write bit field `TN_BFA_RD` - read bit field `TN_BFA_SET` - set bits by mask `TN_BFA_CLR` - clear bits by mask `TN_BFA_INV` - invert bits by mask
reg_name	register name (`PORTA`, `CMCON`, ...).
field_name	structure field name
...	used if only `comm != TN_BFA_RD`. Meaning depends on the `comm`, see comments for specific command: `TN_BFA_WR`, etc.

Usage examples:

int a = 0x02;
//-- Set third bit of the INT0IP field in the IPC0 register:
//   IPC0bits.INT0IP |= (1 << 2);
TN_BFA(TN_BFA_SET, IPC0, INT0IP, (1 << 2));
//-- Clear second bit of the INT0IP field in the IPC0 register:
//   IPC0bits.INT0IP &= ~(1 << 1);
TN_BFA(TN_BFA_CLR, IPC0, INT0IP, (1 << 1));
//-- Invert two less-significant bits of the INT0IP field 
//   in the IPC0 register:
//   IPC0bits.INT0IP ^= 0x03;
TN_BFA(TN_BFA_INV, IPC0, INT0IP, 0x03);
//-- Write value 0x05 to the INT0IP field of the IPC0 register:
//   IPC0bits.INT0IP = 0x05;
TN_BFA(TN_BFA_WR, IPC0, INT0IP, 0x05);
//-- Write value of the variable a to the INT0IP field of the IPC0 
//   register:
//   IPC0bits.INT0IP = a;
TN_BFA(TN_BFA_WR, IPC0, INT0IP, a);
//-- Read the value that is stored in the INT0IP field of the IPC0 
//   register, to the int variable a:
//   int a = IPC0bits.INT0IP;
a = TN_BFA(TN_BFA_RD, IPC0, INT0IP);

Definition at line 154 of file tn_arch_pic24_bfa.h.

#define TN_BFAR	(	comm,
		reg_name,
		lower,
		upper,
		...
	)

Macro for atomic access to the structure bit field specified as a range.

Parameters

comm	command to execute: `TN_BFA_WR` - write bit field `TN_BFA_RD` - read bit field `TN_BFA_SET` - set bits by mask `TN_BFA_CLR` - clear bits by mask `TN_BFA_INV` - invert bits by mask
reg_name	variable name (`PORTA`, `CMCON`, ...). Variable should be in the near memory (first 8 KB)
lower	number of lowest affected bit of the field
upper	number of highest affected bit of the field
...	used if only `comm != TN_BFA_RD`. Meaning depends on the `comm`, see comments for specific command: `TN_BFA_WR`, etc.

Usage examples:

int a = 0x02;
//-- Write constant 0xaa to the least significant byte of the TRISB
//   register:
TN_BFAR(TN_BFA_WR, TRISB, 0, 7, 0xaa);
//-- Invert least significant nibble of the most significant byte 
//   in the register TRISB:
TN_BFAR(TN_BFA_INV, TRISB, 8, 15, 0x0f);
//-- Get 5 least significant bits from the register TRISB and store
//   result to the variable a
a = TN_BFAR(TN_BFA_RD, TRISB, 0, 4);

Definition at line 270 of file tn_arch_pic24_bfa.h.

Detailed Description

Macros

Macro Definition Documentation