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2016-04-28 - Giant Gecko Family - d0053_Rev1.20
418
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on the bus can try to gain control of it. If the current master wishes to make another transfer immediately
after the current, it can start a new transfer directly by transmitting a repeated START condition (Sr)
instead of a STOP followed by a START.
Examples of I
2
C transfers are shown in Figure 16.5 (p. 418) , Figure 16.6 (p. 418) , and Figure 16.7 (p.
418) . The identifiers used are:
• ADDR - Address
• DATA - Data
• S - Start bit
• Sr - Repeated start bit
• P - Stop bit
• W/R - Read(1)/Write(0)
• A - ACK
• N - NACK
Figure 16.5. I
2
C Single Byte Write to Slave
W
S
ADDR
DATA
A
A
P
Figure 16.6. I
2
C Double Byte Read from Slave
R
S
ADDR
DATA
A
DATA
N
A
P
Figure 16.7. I
2
C Single Byte Write, then Repeated Start and Single Byte Read
R
Sr
ADDR
DATA
A
N
P
W
S
ADDR
DATA
A
A
16.3.1.3 Addresses
I
2
C supports both 7-bit and 10-bit addresses. When using 7-bit addresses, the first byte transmitted after
the START-condition contains the address of the slave that the master wants to contact. In the 7-bit
address space, several addresses are reserved. These addresses are summarized in Table 16.1 (p.
418) , and include a General Call address which can be used to broadcast a message to all slaves
on the I
2
C-bus.
Table 16.1. I
2
C Reserved I
2
C Addresses
I
2
C Address
R/W
Description
0000-000
0
General Call address
0000-000
1
START byte
0000-001
X
Reserved for the C-Bus format
0000-010
X
Reserved for a different bus format
0000-011
X
Reserved for future purposes
0000-1XX
X
Reserved for future purposes
1111-1XX
X
Reserved for future purposes
1111-0XX
X
10 Bit slave addressing mode
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