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Defines | |
#define | TWI_SETSPEED 0x0401 |
Set transfer speed. | |
#define | TWI_GETSPEED 0x0402 |
Query transfer speed. | |
#define | TWI_SETSLAVEADDRESS 0x0403 |
Set local slave address. | |
#define | TWI_GETSLAVEADDRESS 0x0404 |
Query local slave address. | |
#define | TWI_SETSTATUS 0x0409 |
Set status. | |
#define | TWI_GETSTATUS 0x040a |
Query status. | |
#define | TWERR_OK 0 |
No error occured. | |
#define | TWERR_TIMEOUT 1 |
Interface timeout. | |
#define | TWERR_BUS 2 |
Bus error. | |
#define | TWERR_IF_LOCKED 3 |
Interface locked. | |
#define | TWERR_SLA_NACK 4 |
No slave response. | |
#define | TWERR_DATA_NACK 5 |
Data not acknowledged. | |
#define | TWSLA_MIN 17 |
Lowest slave address. Addresses below are reserved for special purposes. | |
#define | TWSLA_MAX 79 |
Lowest slave address. Addresses above are reserved for special purposes. | |
#define | TWSLA_BCAST 0 |
Broadcast slave address. | |
#define | TWSLA_HOST 16 |
Host slave address. | |
#define | TWSLA_DEFAULT 193 |
Default slave address. | |
Functions | |
int | TwInit (u_char sla) |
Initialize TWI interface. | |
int | TwIOCtl (int req, void *conf) |
Perform TWI control functions. | |
int | TwMasterTransact (u_char sla, CONST void *txdata, u_short txlen, void *rxdata, u_short rxsiz, u_long tmo) |
Transmit and/or receive data as a master. | |
int | TwMasterError (void) |
Get last master mode error. | |
int | TwSlaveListen (u_char *sla, void *rxdata, u_short rxsiz, u_long tmo) |
Listen for incoming data from a master. | |
int | TwSlaveRespond (void *txdata, u_short txlen, u_long tmo) |
Send response to a master. | |
int | TwSlaveError (void) |
Get last slave mode error. |
#define TWI_SETSPEED 0x0401 |
#define TWI_GETSPEED 0x0402 |
#define TWI_SETSLAVEADDRESS 0x0403 |
#define TWI_GETSLAVEADDRESS 0x0404 |
#define TWI_SETSTATUS 0x0409 |
#define TWI_GETSTATUS 0x040a |
#define TWERR_TIMEOUT 1 |
Interface timeout.
Definition at line 60 of file twif.h.
Referenced by TwMasterTransact(), TwSlaveListen(), and TwSlaveRespond().
#define TWERR_BUS 2 |
#define TWERR_IF_LOCKED 3 |
#define TWERR_SLA_NACK 4 |
#define TWSLA_MIN 17 |
#define TWSLA_MAX 79 |
int TwInit | ( | u_char | sla | ) |
Initialize TWI interface.
The specified slave address is used only, if the local system is running as a slave. Anyway, care must be taken that it doesn't conflict with another connected device.
sla | Slave address, must be specified as a 7-bit address, always lower than 128. |
Definition at line 899 of file twif.c.
Referenced by DS1307Init(), PcfRtcInit(), TwMasterTransact(), and X12Init().
int TwIOCtl | ( | int | req, | |
void * | conf | |||
) |
Perform TWI control functions.
Not implemented in the bit banging version.
req | Requested control function. | |
conf | Points to a buffer that contains any data required for the given control function or receives data from that function. |
Definition at line 827 of file twif.c.
Referenced by TwInit().
int TwMasterTransact | ( | u_char | sla, | |
CONST void * | txdata, | |||
u_short | txlen, | |||
void * | rxdata, | |||
u_short | rxsiz, | |||
u_long | tmo | |||
) |
Transmit and/or receive data as a master.
The two-wire serial interface must have been initialized by calling TwInit() before this function can be used.
sla | Slave address of the destination. This slave address must be specified as a 7-bit address. For example, the PCF8574A may be configured to slave addresses from 0x38 to 0x3F. | |
txdata | Points to the data to transmit. Ignored, if the number of data bytes to transmit is zero. | |
txlen | Number of data bytes to transmit. If zero, then the interface will not send any data to the slave device and will directly enter the master receive mode. | |
rxdata | Points to a buffer, where the received data will be stored. Ignored, if the maximum number of bytes to receive is zero. | |
rxsiz | Maximum number of bytes to receive. Set to zero, if no bytes are expected from the slave device. | |
tmo | Timeout in milliseconds. To disable timeout, set this parameter to NUT_WAIT_INFINITE. |
Definition at line 532 of file twif.c.
References TWERR_SLA_NACK, and TwInit().
Referenced by Cy2239xGetDivider(), Cy2239xGetFreq(), Cy2239xGetPll(), Cy2239xPllEnable(), Cy2239xPllGetFreq(), Cy2239xPllSetFreq(), Cy2239xSetDivider(), Cy2239xSetPll(), DS1307RamWrite(), DS1307RtcReadRegs(), DS1307RtcWrite(), PcfRtcReadRegs(), PcfRtcWrite(), X12EepromRead(), X12EepromWrite(), X12RtcReadRegs(), and X12RtcWrite().
int TwMasterError | ( | void | ) |
Get last master mode error.
You may call this function to determine the specific cause of an error after TwMasterTransact() failed.
Listen for incoming data from a master.
If this function returns without error, the bus is blocked. The caller must immediately process the request and return a response by calling TwSlaveRespond().
sla | Points to a byte variable, which receives the slave address sent by the master. This can be used by the caller to determine whether the the interface has been addressed by a general call or its individual address. | |
rxdata | Points to a data buffer where the received data bytes are stored. | |
rxsiz | Specifies the maximum number of data bytes to receive. | |
tmo | Timeout in milliseconds. To disable timeout, set this parameter to NUT_WAIT_INFINITE. |
Send response to a master.
This function must be called as soon as possible after TwSlaveListen() returned successfully, even if no data needs to be returned. Not doing so will completely block the bus.
txdata | Points to the data to transmit. Ignored, if the number of bytes to transmit is zero. | |
txlen | Number of data bytes to transmit. | |
tmo | Timeout in milliseconds. To disable timeout, set this parameter to NUT_WAIT_INFINITE. |
int TwSlaveError | ( | void | ) |
Get last slave mode error.
You may call this function to determine the specific cause of an error after TwSlaveListen() or TwSlaveRespond() failed.
Definition at line 799 of file twif.c.
References TWERR_BUS.