Calibre UK PICA93LV ユーザーズマニュアル
CALIBRE
Issue 1.3
Page 23
22/07/99
4.4.9.
restart
Function specification
Int restart(int slaveaddress, int setnack)
Parameters are:
int slaveaddress
The address to be accessed via the I2C, e.g. A1H.
int setnack
This controls whether the Parallel I2C Communications Adapter transmits an
Acknowledge down the I2C Bus on reception of a byte. The last byte received
during a transfer must not be acknowledged, in all other cases acknowledge
must be enabled. If setnack = 0 then acknowledge is enabled, if setnack = 1
then acknowledge is disabled. Therefore, if a read (odd numbered) address is
being sent AND only 1 Byte is to be read, setnack should be set to = 1; in all
other cases it must be clear = 0.
Acknowledge down the I2C Bus on reception of a byte. The last byte received
during a transfer must not be acknowledged, in all other cases acknowledge
must be enabled. If setnack = 0 then acknowledge is enabled, if setnack = 1
then acknowledge is disabled. Therefore, if a read (odd numbered) address is
being sent AND only 1 Byte is to be read, setnack should be set to = 1; in all
other cases it must be clear = 0.
Parameters returned
int ErrCode
If the transfer time out occurs error code 8003H is returned otherwise the
status is returned.
status is returned.
Prerequisites
Adapter must be configured using setup. A start and slave address must
have previously been sent using sendaddress.
have previously been sent using sendaddress.
Usually a data pointer would already have been written using writebyte.
Functional description
Sends a start code and the slave address specified and presets the
acknowledge status depending on the value of setnack.
acknowledge status depending on the value of setnack.
The acknowledge is set ready for the data transfer after the address and
hence in read mode (odd address being sent) if only one byte is to be read
the setnack parameter must equal 1. If more than one byte is to be read or if
in write mode (even address being sent) then setnack must equal 0.
hence in read mode (odd address being sent) if only one byte is to be read
the setnack parameter must equal 1. If more than one byte is to be read or if
in write mode (even address being sent) then setnack must equal 0.
The function waits for the address to be sent. Should a time-out occur during
the sending of an address then an error code 8003H is returned, otherwise
the status is returned.
the sending of an address then an error code 8003H is returned, otherwise
the status is returned.
4.4.10.
getstatus
Function specification:
Int getstatus(void)
Parameters are:
None.
Parameters returned
int I2Cstatus
The current value of the bus status.
Prerequisites
Adapter must be configured using setup.
Functional description
The function reads status word from the adapter and returns it.
4.4.11.
recover
Function specification
Int recover(void)
Parameters are:
None.
Parameters returned
int ErrCode.
If the bus recovery failed error code 8006H is returned otherwise the status is
returned.
returned.
Prerequisites
Adapter must be configured using setup.