DSPIC30F2010 MICROCHIP [Microchip Technology], DSPIC30F2010 Datasheet - Page 101

• Manufacturer Part Number: DSPIC30F2010
• Description: High-Performance, 16-Bit Digital Signal Controllers
• Manufacturer: MICROCHIP [Microchip Technology]

16.6
When the STREN bit is ‘1’, the SCLREL bit may be
cleared by software to allow software to control the
clock stretching. The logic will synchronize writes to
the SCLREL bit with the SCL clock. Clearing the
SCLREL bit will not assert the SCL output until the
module detects a falling edge on the SCL output and
SCL is sampled low. If the SCLREL bit is cleared by
the user while the SCL line has been sampled low, the
SCL output will be asserted (held low). The SCL out-
put will remain low until the SCLREL bit is set, and all
other devices on the I
This ensures that a write to the SCLREL bit will not
violate the minimum high time requirement for SCL.
If the STREN bit is ‘0’, a software write to the SCLREL
bit will be disregarded and have no effect on the
SCLREL bit.
16.7
The I
(I
rupt Flag). The MI2CIF interrupt flag is activated on
completion of a master message event. The SI2CIF
interrupt flag is activated on detection of a message
directed to the slave.
16.8
The I
and SCL signals for Fast Mode (400 kHz). The control
bit, DISSLW, enables the user to disable slew rate con-
trol, if desired. It is necessary to disable the slew rate
control for 1 MHz mode.
16.9
The control bit IPMIEN enables the module to support
Intelligent Peripheral Management Interface (IPMI).
When this bit is set, the module accepts and acts upon
all addresses.
16.10 General Call Address Support
The general call address can address all devices.
When this address is used, all devices should, in
theory, respond with an acknowledgement.
The general call address is one of eight addresses
reserved for specific purposes by the I
consists of all 0s with R_W = 0.
The general call address is recognized when the Gen-
eral Call Enable (GCEN) bit is set (I2CCON<15> = 1).
Following a Start bit detection, 8 bits are shifted into
I2CRSR and the address is compared with I2CADD,
and is also compared with the general call address
which is fixed in hardware.
© 2006 Microchip Technology Inc.
2
C Master Interrupt Flag) and SI2CIF (I
2
2
C module generates two interrupt flags, MI2CIF
C standard requires slope control on the SDA
Software Controlled Clock
Stretching (STREN = 1)
Interrupts
Slope Control
IPMI Support
2
C bus have de-asserted SCL.
2
2
C Slave Inter-
C protocol. It
If a general call address match occurs, the I2CRSR is
transferred to the I2CRCV after the eighth clock, the
RBF flag is set, and on the falling edge of the ninth bit
(ACK bit), the master event interrupt flag (MI2CIF) is
set.
When the interrupt is serviced, the source for the inter-
rupt can be checked by reading the contents of the
I2CRCV to determine if the address was device
specific, or a general call address.
16.11 I
As a Master device, six operations are supported.
• Assert a Start condition on SDA and SCL.
• Assert a Restart condition on SDA and SCL.
• Write to the I2CTRN register initiating
• Generate a Stop condition on SDA and SCL.
• Configure the I
• Generate an ACK condition at the end of a
16.12 I
The master device generates all of the serial clock
pulses and the Start and Stop conditions. A transfer is
ended with a Stop condition or with a Repeated Start
condition. Since the Repeated Start condition is also
the beginning of the next serial transfer, the I
not be released.
In Master Transmitter mode, serial data is output
through SDA, while SCL outputs the serial clock. The
first byte transmitted contains the slave address of the
receiving device (7 bits) and the data direction bit. In
this case, the data direction bit (R_W) is logic ‘0’. Serial
data is transmitted 8 bits at a time. After each byte is
transmitted, an ACK bit is received. Start and Stop con-
ditions are output to indicate the beginning and the end
of a serial transfer.
In Master Receive mode, the first byte transmitted con-
tains the slave address of the transmitting device (7
bits) and the data direction bit. In this case, the data
direction bit (R_W) is logic ‘1’. Thus, the first byte trans-
mitted is a 7-bit slave address, followed by a ‘1’ to indi-
cate receive bit. Serial data is received via SDA, while
SCL outputs the serial clock. Serial data is received 8
bits at a time. After each byte is received, an ACK bit is
transmitted. Start and Stop conditions indicate the
beginning and end of transmission.
transmission of data/address.
received byte of data.
2
2
C Master Support
C Master Operation
dsPIC30F2010
2
C port to receive data.
DS70118G-page 99
2
C bus will