EMC1001_15 Datasheet, PDF (6/24 Pages) Microchip Technology – ±1.5°C SMBus Temperature Sensor in Miniature TSOT

EMC1001
3.0 SYSTEM MANAGEMENT BUS
INTERFACE PROTOCOL
A host controller, such as an I/O controller,
communicates with the EMC1001 via the two-wire
serial interface named SMBus. The SMBus interface is
used to read and write registers in the EMC1001, which
is a slave-only device. A detailed timing diagram is
shown in Figure 3-1.
T_LOW
T_HIGH
T_HD:STA
T _SU:STO
SMCLK
SMDATA
T_BUF
T_HD:STA
T _FALL
T _RISE
T_HD:DAT T_SU:DAT
T _SU:STA
P
S
S - Start Condition
S
P - Stop Condition
P
FIGURE 3-1:
System Management Bus Timing Diagram.
The EMC1001 implements a subset of the SMBus
specification and supports Write Byte, Read Byte,
Send Byte, Receive Byte and Alert Response Address
protocols, as shown in the following sections.
3.1 SMBus Write Byte
The Write Byte is used to write one byte of data to a
specific register as shown in Table 3-2.
All protocols in these sections use the convention in
Table 3-1.
TABLE 3-1: PROTOCOL FORMAT
Data Sent to Device Data Sent to the Host
Data sent
Data sent
TABLE 3-2: WRITE BYTE PROTOCOL
START
Slave
Address
WR
ACK
1
7
1
1
Command
8
ACK
1
Data
8
ACK
1
STOP
1
3.2 SMBus Read Byte
The Read Byte protocol is used to read one byte of data
from the registers as shown in Table 3-3.
TABLE 3-3: READ BYTE PROTOCOL
START
Slave
Address
WR
ACK Command ACK
START
Slave
Address
RD
ACK
1
7
1
1
8
1
1
7
1
1
Data
8
NACK STOP
1
1
DS20005411A-page 6
 2015 Microchip Technology Inc.