NXP Semiconductors LPC1768 User Manual

UM10360 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2013. All rights reserved.
User manual Rev. 3 — 19 December 2013 455 of 841
NXP Semiconductors
UM10360
Chapter 19: LPC176x/5x I2C0/1/2
19.9.3 Slave Receiver mode
In the slave receiver mode, a number of data bytes are received from a master transmitter
(see Figure 95
). To initiate the slave receiver mode, I2CON register, the I2ADR registers,
and the I2MASK registers must be configured.
The values on the four I2ADR registers combined with the values on the four I2MASK
registers determines which address(es) the I
2
C block will respond to when slave functions
are enabled. See sections 19.7.2
, 19.7.3, 19.8.7, and 19.8.8 for details.
The I
2
C-bus rate settings do not affect the I
2
C block in the slave mode. I2EN must be set
to logic 1 to enable the I
2
C block. The AA bit must be set to enable the I
2
C block to
acknowledge its own slave address or the General Call address. STA, STO, and SI must
be reset.
When the I2ADR, I2MASK, and I2CON registers have been initialized, the I
2
C block waits
until it is addressed by its own slave address followed by the data direction bit which must
be “0” (W) for the I
2
C block to operate in the slave receiver mode. After its own slave
address and the W bit have been received, the serial interrupt flag (SI) is set and a valid
status code can be read from I2STAT. This status code is used to vector to a state service
routine. The appropriate action to be taken for each of these status codes is detailed in
Table 400
. The slave receiver mode may also be entered if arbitration is lost while the I
2
C
block is in the master mode (see status 0x68 and 0x78).
If the AA bit is reset during a transfer, the I
2
C block will return a not acknowledge (logic 1)
to SDA after the next received data byte. While AA is reset, the I
2
C block does not
respond to its own slave address or a General Call address. However, the I
2
C-bus is still
monitored and address recognition may be resumed at any time by setting AA. This
means that the AA bit may be used to temporarily isolate the I
2
C block from the I
2
C-bus.
Table 397. I2CONSET used to initialize Slave Receiver mode
Bit 7 6 5 4 3 2 1 0
Symbol - I2EN STA STO SI AA - -
Value- 10001- -

NXP Semiconductors LPC1768 Specifications

General

Brand	NXP Semiconductors
Model	LPC1768
Category	Microcontrollers
Language	English