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- ;********************************************************************************************************
- ; uC/CPU
- ; CPU CONFIGURATION & PORT LAYER
- ;
- ; (c) Copyright 2004-2013; Micrium, Inc.; Weston, FL
- ;
- ; All rights reserved. Protected by international copyright laws.
- ;
- ; uC/CPU is provided in source form to registered licensees ONLY. It is
- ; illegal to distribute this source code to any third party unless you receive
- ; written permission by an authorized Micrium representative. Knowledge of
- ; the source code may NOT be used to develop a similar product.
- ;
- ; Please help us continue to provide the Embedded community with the finest
- ; software available. Your honesty is greatly appreciated.
- ;
- ; You can find our product's user manual, API reference, release notes and
- ; more information at https://doc.micrium.com.
- ; You can contact us at www.micrium.com.
- ;********************************************************************************************************
-
- ;********************************************************************************************************
- ;
- ; CPU PORT FILE
- ;
- ; ARM-Cortex-M4
- ; RealView Development Suite
- ; RealView Microcontroller Development Kit (MDK)
- ; ARM Developer Suite (ADS)
- ; Keil uVision
- ;
- ; Filename : cpu_a.asm
- ; Version : V1.30.01.00
- ; Programmer(s) : JJL
- ;********************************************************************************************************
-
-
- ;********************************************************************************************************
- ; PUBLIC FUNCTIONS
- ;********************************************************************************************************
-
- EXPORT CPU_IntDis
- EXPORT CPU_IntEn
-
- EXPORT CPU_SR_Save
- EXPORT CPU_SR_Restore
-
- EXPORT CPU_WaitForInt
- EXPORT CPU_WaitForExcept
-
-
- EXPORT CPU_CntLeadZeros
- EXPORT CPU_CntTrailZeros
- EXPORT CPU_RevBits
-
-
- ;********************************************************************************************************
- ; CODE GENERATION DIRECTIVES
- ;********************************************************************************************************
-
- AREA |.text|, CODE, READONLY, ALIGN=2
- THUMB
- REQUIRE8
- PRESERVE8
-
- ;********************************************************************************************************
- ; DISABLE and ENABLE INTERRUPTS
- ;
- ; Description: Disable/Enable interrupts.
- ;
- ; Prototypes : void CPU_IntDis(void);
- ; void CPU_IntEn (void);
- ;********************************************************************************************************
-
- CPU_IntDis
- CPSID I
- BX LR
-
-
- CPU_IntEn
- CPSIE I
- BX LR
-
-
- ;********************************************************************************************************
- ; CRITICAL SECTION FUNCTIONS
- ;
- ; Description : Disable/Enable interrupts by preserving the state of interrupts. Generally speaking, the
- ; state of the interrupt disable flag is stored in the local variable 'cpu_sr' & interrupts
- ; are then disabled ('cpu_sr' is allocated in all functions that need to disable interrupts).
- ; The previous interrupt state is restored by copying 'cpu_sr' into the CPU's status register.
- ;
- ; Prototypes : CPU_SR CPU_SR_Save (void);
- ; void CPU_SR_Restore(CPU_SR cpu_sr);
- ;
- ; Note(s) : (1) These functions are used in general like this :
- ;
- ; void Task (void *p_arg)
- ; {
- ; CPU_SR_ALLOC(); /* Allocate storage for CPU status register */
- ; :
- ; :
- ; CPU_CRITICAL_ENTER(); /* cpu_sr = CPU_SR_Save(); */
- ; :
- ; :
- ; CPU_CRITICAL_EXIT(); /* CPU_SR_Restore(cpu_sr); */
- ; :
- ; }
- ;********************************************************************************************************
-
- CPU_SR_Save
- MRS R0, PRIMASK ; Set prio int mask to mask all (except faults)
- CPSID I
- BX LR
-
-
- CPU_SR_Restore ; See Note #2.
- MSR PRIMASK, R0
- BX LR
-
-
- ;********************************************************************************************************
- ; WAIT FOR INTERRUPT
- ;
- ; Description : Enters sleep state, which will be exited when an interrupt is received.
- ;
- ; Prototypes : void CPU_WaitForInt (void)
- ;
- ; Argument(s) : none.
- ;********************************************************************************************************
-
- CPU_WaitForInt
- WFI ; Wait for interrupt
- BX LR
-
-
- ;********************************************************************************************************
- ; WAIT FOR EXCEPTION
- ;
- ; Description : Enters sleep state, which will be exited when an exception is received.
- ;
- ; Prototypes : void CPU_WaitForExcept (void)
- ;
- ; Argument(s) : none.
- ;********************************************************************************************************
-
- CPU_WaitForExcept
- WFE ; Wait for exception
- BX LR
-
-
- ;********************************************************************************************************
- ; CPU_CntLeadZeros()
- ; COUNT LEADING ZEROS
- ;
- ; Description : Counts the number of contiguous, most-significant, leading zero bits before the
- ; first binary one bit in a data value.
- ;
- ; Prototype : CPU_DATA CPU_CntLeadZeros(CPU_DATA val);
- ;
- ; Argument(s) : val Data value to count leading zero bits.
- ;
- ; Return(s) : Number of contiguous, most-significant, leading zero bits in 'val'.
- ;
- ; Caller(s) : Application.
- ;
- ; This function is an INTERNAL CPU module function but MAY be called by application
- ; function(s).
- ;
- ; Note(s) : (1) (a) Supports 32-bit data value size as configured by 'CPU_DATA' (see 'cpu.h
- ; CPU WORD CONFIGURATION Note #1').
- ;
- ; (b) For 32-bit values :
- ;
- ; b31 b30 b29 ... b04 b03 b02 b01 b00 # Leading Zeros
- ; --- --- --- --- --- --- --- --- ---------------
- ; 1 x x x x x x x 0
- ; 0 1 x x x x x x 1
- ; 0 0 1 x x x x x 2
- ; : : : : : : : : :
- ; : : : : : : : : :
- ; 0 0 0 1 x x x x 27
- ; 0 0 0 0 1 x x x 28
- ; 0 0 0 0 0 1 x x 29
- ; 0 0 0 0 0 0 1 x 30
- ; 0 0 0 0 0 0 0 1 31
- ; 0 0 0 0 0 0 0 0 32
- ;
- ;
- ; (2) MUST be defined in 'cpu_a.asm' (or 'cpu_c.c') if CPU_CFG_LEAD_ZEROS_ASM_PRESENT is
- ; #define'd in 'cpu_cfg.h' or 'cpu.h'.
- ;********************************************************************************************************
-
- CPU_CntLeadZeros
- CLZ R0, R0 ; Count leading zeros
- BX LR
-
-
- ;********************************************************************************************************
- ; CPU_CntTrailZeros()
- ; COUNT TRAILING ZEROS
- ;
- ; Description : Counts the number of contiguous, least-significant, trailing zero bits before the
- ; first binary one bit in a data value.
- ;
- ; Prototype : CPU_DATA CPU_CntTrailZeros(CPU_DATA val);
- ;
- ; Argument(s) : val Data value to count trailing zero bits.
- ;
- ; Return(s) : Number of contiguous, least-significant, trailing zero bits in 'val'.
- ;
- ; Caller(s) : Application.
- ;
- ; This function is an INTERNAL CPU module function but MAY be called by application
- ; function(s).
- ;
- ; Note(s) : (1) (a) Supports 32-bit data value size as configured by 'CPU_DATA' (see 'cpu.h
- ; CPU WORD CONFIGURATION Note #1').
- ;
- ; (b) For 32-bit values :
- ;
- ; b31 b30 b29 b28 b27 ... b02 b01 b00 # Trailing Zeros
- ; --- --- --- --- --- --- --- --- ----------------
- ; x x x x x x x 1 0
- ; x x x x x x 1 0 1
- ; x x x x x 1 0 0 2
- ; : : : : : : : : :
- ; : : : : : : : : :
- ; x x x x 1 0 0 0 27
- ; x x x 1 0 0 0 0 28
- ; x x 1 0 0 0 0 0 29
- ; x 1 0 0 0 0 0 0 30
- ; 1 0 0 0 0 0 0 0 31
- ; 0 0 0 0 0 0 0 0 32
- ;
- ;
- ; (2) MUST be defined in 'cpu_a.asm' (or 'cpu_c.c') if CPU_CFG_TRAIL_ZEROS_ASM_PRESENT is
- ; #define'd in 'cpu_cfg.h' or 'cpu.h'.
- ;********************************************************************************************************
-
- CPU_CntTrailZeros
- RBIT R0, R0 ; Reverse bits
- CLZ R0, R0 ; Count trailing zeros
- BX LR
-
-
- ;********************************************************************************************************
- ; CPU_RevBits()
- ; REVERSE BITS
- ;
- ; Description : Reverses the bits in a data value.
- ;
- ; Prototypes : CPU_DATA CPU_RevBits(CPU_DATA val);
- ;
- ; Argument(s) : val Data value to reverse bits.
- ;
- ; Return(s) : Value with all bits in 'val' reversed (see Note #1).
- ;
- ; Caller(s) : Application.
- ;
- ; This function is an INTERNAL CPU module function but MAY be called by application function(s).
- ;
- ; Note(s) : (1) The final, reversed data value for 'val' is such that :
- ;
- ; 'val's final bit 0 = 'val's original bit N
- ; 'val's final bit 1 = 'val's original bit (N - 1)
- ; 'val's final bit 2 = 'val's original bit (N - 2)
- ;
- ; ... ...
- ;
- ; 'val's final bit (N - 2) = 'val's original bit 2
- ; 'val's final bit (N - 1) = 'val's original bit 1
- ; 'val's final bit N = 'val's original bit 0
- ;********************************************************************************************************
-
- CPU_RevBits
- RBIT R0, R0 ; Reverse bits
- BX LR
-
-
- ;********************************************************************************************************
- ; CPU ASSEMBLY PORT FILE END
- ;********************************************************************************************************
-
- END
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