Si1000/1/2/3/4/5
Interrupts with Hardware ACK Enabled (EHACK = 1)
S
SLA
R
A
Data Byte
A
Data Byte
N
P
Interrupts with Hardware ACK Disabled (EHACK = 0)
S = START
P = STOP
N = NACK
Received by SMBus
Interface
R = READ
SLA = Slave Address
Transmitted by
SMBus Interface
Figure 24.8. Typical Slave Read Sequence
24.6. SMBus Status Decoding
The current SMBus status can be easily decoded using the SMB0CN register. The appropriate actions to
take in response to an SMBus event depend on whether hardware slave address recognition and ACK
generation is enabled or disabled. Table 24.5 describes the typical actions when hardware slave address
recognition and ACK generation is disabled. Table 24.6 describes the typical actions when hardware slave
address recognition and ACK generation is enabled. In the tables, STATUS VECTOR refers to the four
upper bits of SMB0CN: MASTER, TXMODE, STA, and STO. The shown response options are only the typ-
ical responses; application-specific procedures are allowed as long as they conform to the SMBus specifi-
cation. Highlighted responses are allowed by hardware but do not conform to the SMBus specification.
Rev. 1.0
305