Philips CEM2100/00, Руководство по обслуживанию

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16. Serial Bus Interface(I2C Bus) Ver.-D (SBI)
16.6 Data Transfer of I2C Bus
T
5CL8
Check the AL (Bit3 in the SBISRB), the TRX (Bit6 in the SBISRB), the AAS (Bit2 in the SBISRB),
and the AD0 (Bit1 in the SBISRB) and implements processes according to conditions listed in " Table 16-
4 Operation in the Slave Mode ".
Note: In the slave mode, if the slave address set in I2CAR is "00H", a START Byte "01H" in I
2
C bus standard is recived, the
device detects slave address match and the TRX is set to "1".
16.6.4 Stop condition generation
When the BB is “1”, a sequence of generating a stop condition is started by setting “1” to the MST, TRX and
PIN, and clear “0” to the BB. Do not modify the contents of the MST, TRX, BB, PIN until a stop condition is
generated on a bus.
When a SCL line on a bus is pulled-down by other devices, a serial bus interface circuit generates a stop con-
dition after they release a SCL line.
The time from the releasing SCL line until the generating the STOP condition takes t
LOW
.
Table 16-4 Operation in the Slave Mode
TRX AL AAS AD0 Conditions Process
1
1 1 0
A serial bus interface circuit loses arbitra-
tion when transmitting a slave address.
And receives a slave address of which the
value of the direction bit sent from another
master is "1".
Set the number of bits in 1 word to the BC
and write transmitted data to the SBIDBR.
0
1 0
In the slave receiver mode, a serial bus
interface circuit receives a slave address
of which the value of the direction bit sent
from the master is "1".
0 0
In the slave transmitter mode, 1-word data
is transmitted.
Test the LRB. If the LRB is set to "1", set
the PIN to "1" since the receiver does not
request next data. Then, clear the TRX to
"0" to release the bus. If the LRB is set to
"0", set the number of bits in 1 word to the
BC and write transmitted data to the
SBIDBR since the receiver requests next
data.
0
1
1 1/0
A serial bus interface circuit loses arbitra-
tion when transmitting a slave address.
And receives a slave address of which the
value of the direction bit sent from another
master is "0" or receives a "GENERAL
CALL".
Read the SBIDBR for setting the PIN to
"1" (Reading dummy data) or write "1" to
the PIN.
0 0
A serial bus interface circuit loses arbitra-
tion when transmitting a slave address or
data. And terminates transferring word
data.
A serial bus interface circuit is changed to
slave mode. To clear AL to "0", read the
SBIDBR or write the data to SBIDBR.
0
1 1/0
In the slave receiver mode, a serial bus
interface circuit receives a slave address
of which the value of the direction bit sent
from the master is "0" or receives "GEN-
ERAL CALL".
Read the SBIDBR for setting the PIN to
"1" (Reading dummy data) or write "1" to
the PIN.
0 1/0
In the slave receiver mode, a serial bus
interface circuit terminates receiving of 1-
word data.
Set the number of bits in 1-word to the BC
and read received data from the SBIDBR.