Slave Receiver Mode - Texas Instruments CC253x User Manual

www.ti.com
Status
Code Status of the
2
(Value of I C
I2CSTAT)
0xC8 Last data byte
has been
transmitted;
ACK has been
received.
2
20.1.4.1.2 I C Slave Receiver Mode
Slave receiver mode is entered when the slave address transmitted by the master is identical to its own
address and a cleared R/W bit is received. In slave receiver mode, serial data bits received on SDA are
shifted in with the clock pulses that are generated by the master device. The slave device does not
generate the clock, but it can hold SCL low if intervention of the CPU is required after a byte has been
received.
If the slave interrupt is triggered from the master, the I
and I2CCFG.SI is set. After the first data byte is received, the interrupt flag I2CCFG.SI is set again. The
2
I C module automatically acknowledges the received data.
While the I2CCFG.SI flag is set, the bus is stalled by holding SCL low.
When the master generates a STOP condition, the I2CCFG.STO flag is set.
If the master generates a repeated START condition, the I
reception state.
Table 20-2 provides more details regarding slave receiver operation.
Status
Code Status of the
2
(Value of I C
I2CSTAT)
0x60 Own SLA+W
has been
received; ACK
has been
returned.
0x68 Arbitration lost
in SLA+R/W as
master; own
SLA+W has
been received,
ACK returned.
0x70 General-call
address (0x00)
has been
received; ACK
has been
returned
SWRU191F – April 2009 – Revised April 2014
Submit Documentation Feedback
Table 20-1. Slave Transmitter Mode (continued)
Application Software Response
To I2CCFG
To or From
I2CDATA
STA STO
No action 0 0
or 0 0
no action
or 1 0
no action
or 1 0
no action
Table 20-2. Slave Receiver Mode
Application Software Response
To I2CCFG
To or From
I2CDATA
STA STO
No action X 0
or X 0
no action
No action X 0
or X 0
no action
No action X 0
or X 0
no action
Copyright © 2009–2014, Texas Instruments Incorporated
Next Action Taken by I
SI AA
0 0 Switched to not-addressed SLV mode; no
recognition of own SLA or general-call address
0 1 Switched to not-addressed SLV mode; own SLA or
general call address is recognized.
0 0 Switched to not-addressed SLV mode; no
recognition of own SLA or general call address;
START condition is transmitted when the bus
becomes free.
0 1 Switched to not-addressed SLV mode; own SLA or
general call address is recognized; START
condition is transmitted when the bus becomes
free.
2
C module is automatically configured as a receiver
2
C state machine returns to its address
Next Action Taken by I
SI AA
0 0 Data byte is received and not-ACK is returned
0 1 Data byte is received and ACK is returned.
0 0 Data byte is received and not-ACK is returned.
0 1 Data byte is received and ACK is returned.
0 0 Data byte is received and not-ACK is returned.
0 1 Data byte is received and ACK is returned.
Operation
2
C Hardware
2
C Hardware
173
2
I C