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[/] [neorv32/] [trunk/] [sw/] [lib/] [source/] [neorv32_twi.c] - Blame information for rev 3

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// #################################################################################################
// # << NEORV32: neorv32_twi.c - Two-Wire Interface Master (TWI) HW Driver >>                      #
// # ********************************************************************************************* #
// # BSD 3-Clause License                                                                          #
// #                                                                                               #
// # Copyright (c) 2020, Stephan Nolting. All rights reserved.                                     #
// #                                                                                               #
// # Redistribution and use in source and binary forms, with or without modification, are          #
// # permitted provided that the following conditions are met:                                     #
// #                                                                                               #
// # 1. Redistributions of source code must retain the above copyright notice, this list of        #
// #    conditions and the following disclaimer.                                                   #
// #                                                                                               #
// # 2. Redistributions in binary form must reproduce the above copyright notice, this list of     #
// #    conditions and the following disclaimer in the documentation and/or other materials        #
// #    provided with the distribution.                                                            #
// #                                                                                               #
// # 3. Neither the name of the copyright holder nor the names of its contributors may be used to  #
// #    endorse or promote products derived from this software without specific prior written      #
// #    permission.                                                                                #
// #                                                                                               #
// # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS   #
// # OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF               #
// # MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE    #
// # COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,     #
// # EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE #
// # GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED    #
// # AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING     #
// # NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED  #
// # OF THE POSSIBILITY OF SUCH DAMAGE.                                                            #
// # ********************************************************************************************* #
// # The NEORV32 Processor - https://github.com/stnolting/neorv32              (c) Stephan Nolting #
// #################################################################################################
 
 
/**********************************************************************//**
 * @file neorv32_twi.c
 * @author Stephan Nolting
 * @brief Two-Wire Interface Master (TWI) HW driver source file.
 *
 * @note These functions should only be used if the TWI unit was synthesized (IO_TWI_USE = true).
 **************************************************************************/
 
#include "neorv32.h"
#include "neorv32_twi.h"
 
 
/**********************************************************************//**
 * Check if TWI unit was synthesized.
 *
 * @return 0 if TWI was not synthesized, 1 if TWI is available.
 **************************************************************************/
int neorv32_twi_available(void) {
 
  if (neorv32_cpu_csr_read(CSR_MFEATURES) & (1 << CPU_MFEATURES_IO_TWI)) {
    return 1;
  }
  else {
    return 0;
  }
}
 
 
/**********************************************************************//**
 * Enable and configure TWI controller. The TWI control register bits are listed in #NEORV32_TWI_CT_enum.
 *
 * @param[in] prsc Clock prescaler select (0..7). See #NEORV32_CLOCK_PRSC_enum.
 * @param[in] irq_en Enable transfer-done interrupt when 1.
 **************************************************************************/
void neorv32_twi_setup(uint8_t prsc, uint8_t irq_en) {
 
  TWI_CT = 0; // reset
 
  uint32_t ct_enable = 1;
  ct_enable = ct_enable << TWI_CT_EN;
 
  uint32_t ct_prsc = (uint32_t)(prsc & 0x07);
  ct_prsc = ct_prsc << TWI_CT_PRSC0;
 
  uint32_t ct_irq = (uint32_t)(irq_en & 0x01);
  ct_irq = ct_irq << TWI_CT_IRQ_EN;
 
  TWI_CT = ct_enable | ct_prsc | ct_irq;
}
 
 
/**********************************************************************//**
 * Disable TWI controller.
 **************************************************************************/
void neorv32_twi_disable(void) {
 
  TWI_CT &= ~((uint32_t)(1 << TWI_CT_IRQ_EN));
}
 
 
/**********************************************************************//**
 * Activate sending ACKs by master (MACK).
 **************************************************************************/
void neorv32_twi_mack_enable(void) {
 
  TWI_CT |= ((uint32_t)(1 << TWI_CT_MACK));
}
 
 
/**********************************************************************//**
 * Deacivate sending ACKs by master (MACK).
 **************************************************************************/
void neorv32_twi_mack_disable(void) {
 
  TWI_CT &= ~((uint32_t)(1 << TWI_CT_MACK));
}
 
 
 /**********************************************************************//**
 * Generate START condition and send first byte (address including R/W bit).
 *
 * @note Blocking function.
 *
 * @param[in] a Data byte including 7-bit address and R/W-bit (lsb).
 * @return 0: ACK received, 1: NACK received.
 **************************************************************************/
int neorv32_twi_start_trans(uint8_t a) {
 
  neorv32_twi_generate_start(); // generate START condition
 
  TWI_DATA = (uint32_t)a; // send address
  while(TWI_CT & (1 << TWI_CT_BUSY)); // wait until idle again
 
  // check for ACK/NACK
  if (TWI_CT & (1 << TWI_CT_ACK))
    return 0; // ACK received
  else
    return 1; // NACK received
}
 
 
 /**********************************************************************//**
 * Send data byte and also receive data byte (can be read via neorv32_twi_get_data()).
 *
 * @note Blocking function.
 *
 * @param[in] d Data byte to be send.
 * @return 0: ACK received, 1: NACK received.
 **************************************************************************/
int neorv32_twi_trans(uint8_t d) {
 
  TWI_DATA = (uint32_t)d; // send data
  while(TWI_CT & (1 << TWI_CT_BUSY)); // wait until idle again
 
  // check for ACK/NACK
  if (TWI_CT & (1 << TWI_CT_ACK))
    return 0; // ACK received
  else
    return 1; // NACK received
}
 
 
 /**********************************************************************//**
 * Get received data from last transmission.
 *
 * @return 0: Last received data byte.
 **************************************************************************/
uint8_t neorv32_twi_get_data(void) {
 
  return (uint8_t)TWI_DATA; // get RX data from previous transmission
}
 
 
 /**********************************************************************//**
 * Generate STOP condition.
 *
 * @note Blocking function.
 **************************************************************************/
void neorv32_twi_generate_stop(void) {
 
  TWI_CT |= (uint32_t)(1 << TWI_CT_STOP); // generate STOP condition
  while(TWI_CT & (1 << TWI_CT_BUSY)); // wait until idle again
}
 
 
 /**********************************************************************//**
 * Generate START condition.
 *
 * @note Blocking function.
 **************************************************************************/
void neorv32_twi_generate_start(void) {
 
  TWI_CT |= (1 << TWI_CT_START); // generate START condition
  while(TWI_CT & (1 << TWI_CT_BUSY)); // wait until idle again
}

Line No.	Rev	Author	Line
1	2	zero_gravi	`// #################################################################################################`
2			`// # << NEORV32: neorv32_twi.c - Two-Wire Interface Master (TWI) HW Driver >> #`
3			`// # ********************************************************************************************* #`
4			`// # BSD 3-Clause License #`
5			`// # #`
6			`// # Copyright (c) 2020, Stephan Nolting. All rights reserved. #`
7			`// # #`
8			`// # Redistribution and use in source and binary forms, with or without modification, are #`
9			`// # permitted provided that the following conditions are met: #`
10			`// # #`
11			`// # 1. Redistributions of source code must retain the above copyright notice, this list of #`
12			`// # conditions and the following disclaimer. #`
13			`// # #`
14			`// # 2. Redistributions in binary form must reproduce the above copyright notice, this list of #`
15			`// # conditions and the following disclaimer in the documentation and/or other materials #`
16			`// # provided with the distribution. #`
17			`// # #`
18			`// # 3. Neither the name of the copyright holder nor the names of its contributors may be used to #`
19			`// # endorse or promote products derived from this software without specific prior written #`
20			`// # permission. #`
21			`// # #`
22			`// # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS #`
23			`// # OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF #`
24			`// # MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE #`
25			`// # COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, #`
26			`// # EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE #`
27			`// # GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED #`
28			`// # AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING #`
29			`// # NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED #`
30			`// # OF THE POSSIBILITY OF SUCH DAMAGE. #`
31			`// # ********************************************************************************************* #`
32			`// # The NEORV32 Processor - https://github.com/stnolting/neorv32 (c) Stephan Nolting #`
33			`// #################################################################################################`
34
35
36			`/********************************************************************//`
37			`* @file neorv32_twi.c`
38			`* @author Stephan Nolting`
39			`* @brief Two-Wire Interface Master (TWI) HW driver source file.`
40			`*`
41			`* @note These functions should only be used if the TWI unit was synthesized (IO_TWI_USE = true).`
42			`**************************************************************************/`
43
44			`#include "neorv32.h"`
45			`#include "neorv32_twi.h"`
46
47
48			`/********************************************************************//`
49			`* Check if TWI unit was synthesized.`
50			`*`
51			`* @return 0 if TWI was not synthesized, 1 if TWI is available.`
52			`**************************************************************************/`
53			`int neorv32_twi_available(void) {`
54
55			`if (neorv32_cpu_csr_read(CSR_MFEATURES) & (1 << CPU_MFEATURES_IO_TWI)) {`
56			`return 1;`
57			`}`
58			`else {`
59			`return 0;`
60			`}`
61			`}`
62
63
64			`/********************************************************************//`
65			`* Enable and configure TWI controller. The TWI control register bits are listed in #NEORV32_TWI_CT_enum.`
66			`*`
67			`* @param[in] prsc Clock prescaler select (0..7). See #NEORV32_CLOCK_PRSC_enum.`
68			`* @param[in] irq_en Enable transfer-done interrupt when 1.`
69			`**************************************************************************/`
70			`void neorv32_twi_setup(uint8_t prsc, uint8_t irq_en) {`
71
72			`TWI_CT = 0; // reset`
73
74			`uint32_t ct_enable = 1;`
75			`ct_enable = ct_enable << TWI_CT_EN;`
76
77			`uint32_t ct_prsc = (uint32_t)(prsc & 0x07);`
78			`ct_prsc = ct_prsc << TWI_CT_PRSC0;`
79
80			`uint32_t ct_irq = (uint32_t)(irq_en & 0x01);`
81			`ct_irq = ct_irq << TWI_CT_IRQ_EN;`
82
83			`TWI_CT = ct_enable \| ct_prsc \| ct_irq;`
84			`}`
85
86
87			`/********************************************************************//`
88			`* Disable TWI controller.`
89			`**************************************************************************/`
90			`void neorv32_twi_disable(void) {`
91
92			`TWI_CT &= ~((uint32_t)(1 << TWI_CT_IRQ_EN));`
93			`}`
94
95
96			`/********************************************************************//`
97			`* Activate sending ACKs by master (MACK).`
98			`**************************************************************************/`
99			`void neorv32_twi_mack_enable(void) {`
100
101			`TWI_CT \|= ((uint32_t)(1 << TWI_CT_MACK));`
102			`}`
103
104
105			`/********************************************************************//`
106			`* Deacivate sending ACKs by master (MACK).`
107			`**************************************************************************/`
108			`void neorv32_twi_mack_disable(void) {`
109
110			`TWI_CT &= ~((uint32_t)(1 << TWI_CT_MACK));`
111			`}`
112
113
114			`/********************************************************************//`
115			`* Generate START condition and send first byte (address including R/W bit).`
116			`*`
117			`* @note Blocking function.`
118			`*`
119			`* @param[in] a Data byte including 7-bit address and R/W-bit (lsb).`
120			`* @return 0: ACK received, 1: NACK received.`
121			`**************************************************************************/`
122			`int neorv32_twi_start_trans(uint8_t a) {`
123
124			`neorv32_twi_generate_start(); // generate START condition`
125
126			`TWI_DATA = (uint32_t)a; // send address`
127			`while(TWI_CT & (1 << TWI_CT_BUSY)); // wait until idle again`
128
129			`// check for ACK/NACK`
130			`if (TWI_CT & (1 << TWI_CT_ACK))`
131			`return 0; // ACK received`
132			`else`
133			`return 1; // NACK received`
134			`}`
135
136
137			`/********************************************************************//`
138			`* Send data byte and also receive data byte (can be read via neorv32_twi_get_data()).`
139			`*`
140			`* @note Blocking function.`
141			`*`
142			`* @param[in] d Data byte to be send.`
143			`* @return 0: ACK received, 1: NACK received.`
144			`**************************************************************************/`
145			`int neorv32_twi_trans(uint8_t d) {`
146
147			`TWI_DATA = (uint32_t)d; // send data`
148			`while(TWI_CT & (1 << TWI_CT_BUSY)); // wait until idle again`
149
150			`// check for ACK/NACK`
151			`if (TWI_CT & (1 << TWI_CT_ACK))`
152			`return 0; // ACK received`
153			`else`
154			`return 1; // NACK received`
155			`}`
156
157
158			`/********************************************************************//`
159			`* Get received data from last transmission.`
160			`*`
161			`* @return 0: Last received data byte.`
162			`**************************************************************************/`
163			`uint8_t neorv32_twi_get_data(void) {`
164
165			`return (uint8_t)TWI_DATA; // get RX data from previous transmission`
166			`}`
167
168
169			`/********************************************************************//`
170			`* Generate STOP condition.`
171			`*`
172			`* @note Blocking function.`
173			`**************************************************************************/`
174			`void neorv32_twi_generate_stop(void) {`
175
176			`TWI_CT \|= (uint32_t)(1 << TWI_CT_STOP); // generate STOP condition`
177			`while(TWI_CT & (1 << TWI_CT_BUSY)); // wait until idle again`
178			`}`
179
180
181			`/********************************************************************//`
182			`* Generate START condition.`
183			`*`
184			`* @note Blocking function.`
185			`**************************************************************************/`
186			`void neorv32_twi_generate_start(void) {`
187
188			`TWI_CT \|= (1 << TWI_CT_START); // generate START condition`
189			`while(TWI_CT & (1 << TWI_CT_BUSY)); // wait until idle again`
190			`}`

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[/] [neorv32/] [trunk/] [sw/] [lib/] [source/] [neorv32_twi.c] - Blame information for rev 3