1 /*
2 *-------------------------------------------------------------------------------
3 * \file cy_syslib_iar.c
4 * \version 2.20
5 *
6 * \brief Assembly routines for IAR.
7 *
8 *-------------------------------------------------------------------------------
9 * Copyright 2016-2020 Cypress Semiconductor Corporation
10 * SPDX-License-Identifier: Apache-2.0
11 *
12 * Licensed under the Apache License, Version 2.0 (the "License");
13 * you may not use this file except in compliance with the License.
14 * You may obtain a copy of the License at
15 *
16 * http://www.apache.org/licenses/LICENSE-2.0
17 *
18 * Unless required by applicable law or agreed to in writing, software
19 * distributed under the License is distributed on an "AS IS" BASIS,
20 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
21 * See the License for the specific language governing permissions and
22 * limitations under the License.
23 *
24 * Derived from ../armclang/cy_syslib_mdk.s
25 */
26
27 #include "system_psoc6.h"
28
29 /*
30 *-------------------------------------------------------------------------------
31 * Function Name: Cy_SysLib_DelayCycles
32 *-------------------------------------------------------------------------------
33 *
34 * Summary:
35 * Delays for the specified number of cycles.
36 *
37 * Parameters:
38 * uint32_t cycles: The number of cycles to delay.
39 *
40 *-------------------------------------------------------------------------------
41 */
42
Cy_SysLib_DelayCycles(uint32_t cycles)43 void Cy_SysLib_DelayCycles(uint32_t cycles)
44 {
45 asm("ADDS %0, %0, #2 ; 1 2 Round to the nearest multiple of 4. \n"
46 "LSRS %0, %0, #2 ; 1 2 Divide by 4 and set flags. \n"
47 "BEQ Cy_DelayCycles_done ; 2 2 Skip if 0. \n"
48 "Cy_DelayCycles_loop: \n"
49 "ADDS %0, %0, #1 ; 1 2 Increment the counter. \n"
50 "SUBS %0, %0, #2 ; 1 2 Decrement the counter by 2. \n"
51 "BNE Cy_DelayCycles_loop ; (1)2 2 2 CPU cycles (if branch is taken). \n"
52 "NOP ; 1 2 Loop alignment padding. \n"
53 "Cy_DelayCycles_done: \n"
54 ";BX lr ; 3 2 \n"
55 :
56 : "r" (cycles));
57 }
58
59
60 /*
61 *-------------------------------------------------------------------------------
62 * Function Name: Cy_SysLib_EnterCriticalSection
63 *-------------------------------------------------------------------------------
64 *
65 * Summary:
66 * Cy_SysLib_EnterCriticalSection disables interrupts and returns a value
67 * indicating whether interrupts were previously enabled.
68 *
69 * Note Implementation of Cy_SysLib_EnterCriticalSection manipulates the IRQ
70 * enable bit with interrupts still enabled. The test and set of the interrupt
71 * bits are not atomic. Therefore, to avoid a corrupting processor state, it must
72 * be the policy that all interrupt routines restore the interrupt enable bits as
73 * they were found on entry.
74 *
75 * Return:
76 * uint8_t
77 * Returns 0 if interrupts were previously enabled or 1 if interrupts
78 * were previously disabled.
79 *
80 *-------------------------------------------------------------------------------
81 */
82
Cy_SysLib_EnterCriticalSection(void)83 uint8_t Cy_SysLib_EnterCriticalSection(void)
84 {
85 uint8_t mask;
86 asm("MRS %0, PRIMASK ; Save and return an interrupt state. \n"
87 "CPSID I ; Disable the interrupts. \n"
88 : "=r" (mask)
89 :);
90 return mask;
91 }
92
93 /*
94 *-------------------------------------------------------------------------------
95 * Function Name: Cy_SysLib_ExitCriticalSection
96 *-------------------------------------------------------------------------------
97 *
98 * Summary:
99 * Cy_SysLib_ExitCriticalSection re-enables interrupts if they were enabled
100 * before Cy_SysLib_EnterCriticalSection was called. The argument should be the
101 * value returned from Cy_SysLib_EnterCriticalSection.
102 *
103 * Parameters:
104 * uint8_t savedIntrStatus:
105 * The saved interrupt status returned by the Cy_SysLib_EnterCriticalSection
106 * function.
107 *
108 *-------------------------------------------------------------------------------
109 */
110
Cy_SysLib_ExitCriticalSection(uint8_t savedIntrStatus)111 void Cy_SysLib_ExitCriticalSection(uint8_t savedIntrStatus)
112 {
113 asm("MSR PRIMASK, %0 ; Restore the interrupt state. \n"
114 :
115 : "r" (savedIntrStatus)
116 );
117 }
118
