gem5  v20.1.0.0
bus.hh
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37 
38 
43 #ifndef __DEV_I2C_BUS_HH__
44 #define __DEV_I2C_BUS_HH__
45 
46 #include <map>
47 
48 #include "dev/io_device.hh"
49 #include "params/I2CBus.hh"
50 
51 class I2CDevice;
52 
53 class I2CBus : public BasicPioDevice
54 {
55  protected:
56 
57  enum I2CState {
62  };
63 
71  static const int SB_CONTROLS = 0x0;
73  static const int SB_CONTROLC = 0x4;
74 
76  uint8_t scl;
78  uint8_t sda;
79 
85 
90  int currBit;
91 
97  uint8_t i2cAddr;
98 
100  uint8_t message;
101 
107  std::map<uint8_t, I2CDevice*> devices;
108 
115  void updateSignals(PacketPtr pkt);
116 
123  bool isClockSet(PacketPtr pkt) const;
124 
131  bool isStart(PacketPtr pkt) const;
132 
139  bool isEnd(PacketPtr pkt) const;
140 
141  public:
142 
143  I2CBus(const I2CBusParams* p);
144 
145  Tick read(PacketPtr pkt) override;
146  Tick write(PacketPtr pkt) override;
147 
148  void serialize(CheckpointOut &cp) const override;
149  void unserialize(CheckpointIn &cp) override;
150 };
151 
152 #endif // __DEV_I2C_BUS_HH__
I2CDevice
Definition: device.hh:50
I2CBus::unserialize
void unserialize(CheckpointIn &cp) override
Unserialize an object.
Definition: bus.cc:227
io_device.hh
I2CBus::message
uint8_t message
8-bit buffer used to send and receive messages bit by bit.
Definition: bus.hh:100
I2CBus::i2cAddr
uint8_t i2cAddr
Key used to access a device in the slave devices map.
Definition: bus.hh:97
I2CBus::scl
uint8_t scl
I2C clock wire (0, 1).
Definition: bus.hh:76
I2CBus::updateSignals
void updateSignals(PacketPtr pkt)
Update data (sda) and clock (scl) to match any transitions specified by pkt.
Definition: bus.cc:172
I2CBus::RECEIVING_DATA
@ RECEIVING_DATA
Definition: bus.hh:60
I2CBus::read
Tick read(PacketPtr pkt) override
Reads will always be to SB_CONTROLS.
Definition: bus.cc:70
I2CBus::sda
uint8_t sda
I2C data wire (0, 1)
Definition: bus.hh:78
I2CBus::currBit
int currBit
Order of the bit of the current message that is being sent or received (0 - 7).
Definition: bus.hh:90
Tick
uint64_t Tick
Tick count type.
Definition: types.hh:63
I2CBus::I2CBus
I2CBus(const I2CBusParams *p)
4KB - see e.g.
Definition: bus.cc:54
I2CBus::state
enum I2CState state
State used by I2CBus::write to determine what stage of an i2c transmission it is currently in.
Definition: bus.hh:84
I2CBus::isStart
bool isStart(PacketPtr pkt) const
i2c start signal check
Definition: bus.cc:200
cp
Definition: cprintf.cc:40
I2CBus
Definition: bus.hh:53
I2CBus::serialize
void serialize(CheckpointOut &cp) const override
Serialize an object.
Definition: bus.cc:215
I2CBus::RECEIVING_ADDR
@ RECEIVING_ADDR
Definition: bus.hh:59
I2CBus::SB_CONTROLS
static const int SB_CONTROLS
Read [and Set] serial control bits: Bit [0] is SCL Bit [1] is SDA.
Definition: bus.hh:71
I2CBus::SENDING_DATA
@ SENDING_DATA
Definition: bus.hh:61
I2CBus::isEnd
bool isEnd(PacketPtr pkt) const
i2c end signal check
Definition: bus.cc:208
I2CBus::write
Tick write(PacketPtr pkt) override
The default i2c bus driver used by the realview pbx board writes to this device one bit at a time.
Definition: bus.cc:89
I2CBus::SB_CONTROLC
static const int SB_CONTROLC
Clear control bits.
Definition: bus.hh:73
Packet
A Packet is used to encapsulate a transfer between two objects in the memory system (e....
Definition: packet.hh:257
BasicPioDevice
Definition: io_device.hh:150
CheckpointOut
std::ostream CheckpointOut
Definition: serialize.hh:63
I2CBus::IDLE
@ IDLE
Definition: bus.hh:58
I2CBus::devices
std::map< uint8_t, I2CDevice * > devices
All the slave i2c devices that are connected to this bus.
Definition: bus.hh:107
MipsISA::p
Bitfield< 0 > p
Definition: pra_constants.hh:323
CheckpointIn
Definition: serialize.hh:67
I2CBus::isClockSet
bool isClockSet(PacketPtr pkt) const
Clock set check.
Definition: bus.cc:192
I2CBus::I2CState
I2CState
Definition: bus.hh:57

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