PIC14000T-04/SS View Datasheet(PDF) - Microchip Technology
Part Name
Description
MFG CO.
'PIC14000T-04/SS' PDF : 153 Pages View PDF
PIC14000
When a master does not wish to relinquish the bus (by
generating a STOP condition), a repeated START (Sr)
must be generated. This condition is identical to the
START (SDA goes high-to-low while SCL is high), but
occurs after a data transfer acknowledge pulse (not the
bus-free state). This allows a master to send
“commands” to the slave and then receive the
requested information or to address a different slave
device. This sequence is shown in Figure 7-10.
FIGURE 7-8: MASTER - TRANSMITTER SEQUENCE
For 7-bit address:
S Slave Address R/W A DATA A DATA A/A P
"0" (write)
data transferred
(n bytes - acknowledge)
A master transmitter addresses a slave receiver with a
7-bit address. The transfer direction is not changed.
From master to slave
From slave to master
A = acknowledge (SDA low)
A = not acknowledge (SDA high)
S = START condition
P = STOP condition
For 10-bit address:
S Slave Address R/W A1 Slave Address A2
first 7 bits
second byte
(write)
Data A Data A/A P
A master transmitter addresses a slave receiver with a
10-bit address.
FIGURE 7-9: MASTER - RECEIVER SEQUENCE
For 7-bit address:
S Slave Address R/W A DATA A DATA A P
(read)
data transferred
(n bytes - acknowledge)
A master reads a slave immediately after the first byte.
From master to slave
From slave to master
A = acknowledge (SDA low)
A = not acknowledge (SDA high)
S = START condition
P = STOP condition
For 10-bit address:
S Slave Address R/W A1 Slave Address A2
first 7 bits
second byte
(write)
Sr Slave Address R/W A3 Data A
first 7 bits
(read)
Data A P
A master transmitter addresses a slave receiver with a
10-bit address.
FIGURE 7-10: COMBINED FORMAT
(read or write)
(n bytes + acknowledge)
S Slave Address R/W A DATA A/A Sr Slave Address R/W A DATA A/A P
(read)
Sr = repeated (write)
START condition
Direction of transfer
may change at this point
Transfer direction of data and acknowledgement bits depends on R/W bits.
Combined Format:
S Slave Address R/W A Slave Address A Data A
first 7 bits
second byte
(write)
Data A/A Sr Slave Address R/W A Data A
first 7 bits
(read)
Combined format - A master addresses a slave with a 10-bit address, then transmits
data to this slave and reads data from this slave.
From master to slave
From slave to master
A = acknowledge (SDA low)
A = not acknowledge (SDA high)
S = START condition
P = STOP condition
Data A P
DS40122B-page 46
Preliminary
© 1996 Microchip Technology Inc.
Share Link: 
