PIC16F726-I/SP Microchip Technology Inc., PIC16F726-I/SP Datasheet - Page 171

• Manufacturer Part Number: PIC16F726-I/SP
• Description: 28 PIN, 14 KB FLASH, 1.8V-5.5V, 16 MHZ INT. OSC.
• Manufacturer: Microchip Technology Inc.

Specifications of PIC16F726-I/SP

• A/d Inputs: 11-Channel, 8-Bit
• Comparators: 2
• Cpu Speed: 5 MIPS
• Eeprom Memory: 0 Bytes
• Frequency: 20 MHz
• Input Output: 25
• Interface: I2C/SPI/USART
• Memory Type: Flash
• Number Of Bits: 8
• Package Type: 28-pin SPDIP
• Programmable Memory: 14K Bytes
• Ram Size: 368 Bytes
• Resistance, Drain To Source On: Bytes
• Serial Interface: I2C, SPI, AUSART
• Speed: 20 MHz
• Timers: 2-8-bit, 1-16-bit
• Voltage, Range: 1.8-5.5 V
• Lead Free Status / Rohs Status: RoHS Compliant part Electrostatic Device

17.1.2
For any SPI device acting as a slave, the data is
transmitted and received as external clock pulses
appear on SCK pin. This external clock must meet the
minimum high and low times as specified in the
electrical specifications.
17.1.2.1
The SSP consists of a transmit/receive shift register
(SSPSR) and a buffer register (SSPBUF). The SSPSR
shifts the data in and out of the device, MSb first. The
SSPBUF holds the data that was written to the SSPSR
until the received data is ready.
The slave has no control as to when data will be
clocked in or out of the device. All data that is to be
transmitted, to a master or another slave, must be
loaded into the SSPBUF register before the first clock
pulse is received.
Once eight bits of data have been received:
• Received byte is moved to the SSPBUF register
• BF bit of the SSPSTAT register is set
• SSPIF bit of the PIR1 register is set
Any
transmission/reception of data will be ignored and the
Write Collision Detect bit, WCOL of the SSPCON
register, will be set. User software must clear the
WCOL bit so that it can be determined if the following
write(s)
successfully.
The user’s firmware must read SSPBUF, clearing the
BF flag, or the SSPOV bit of the SSPCON register will
be set with the reception of the next byte and
communication will be disabled.
A SPI module transmits and receives at the same time,
occasionally
transmitted/received. It is up to the user to determine
which data is to be used and what can be discarded.
© 2008 Microchip Technology Inc.
write
to
SLAVE MODE
Slave Mode Operation
to
the
causing
the
SSPBUF
SSPBUF
dummy
register
register
data
completed
to
during
Preliminary
be
PIC16F72X/PIC16LF72X
17.1.2.2
To enable the serial port, the SSPEN bit of the
SSPCON register must be set. If a Slave mode of
operation is selected in the SSPM bits of the SSPCON
register, the SDI, SDO, SCK pins will be assigned as
serial port pins.
For these pins to function as serial port pins, they must
have their corresponding data direction bits set or
cleared in the associated TRIS register as follows:
• SDI configured as input
• SDO configured as output
• SCK configured as input
Optionally, a fourth pin, Slave Select (SS) may be used
in Slave mode. Slave Select may be configured to
operate on one of the following pins via the SSSEL bit in
the APFCON register.
• RA5/AN4/SS
• RA0/AN0/SS
Upon selection of a Slave Select pin, the appropriate
bits must be set in the ANSELA and TRISA registers.
Slave Select must be set as an input by setting the
corresponding bit in TRISA, and digital I/O must be
enabled on the SS pin by clearing the corresponding bit
of the ANSELA register.
17.1.2.3
When initializing the SSP module to SPI Slave mode,
compatibility must be ensured with the master device.
This is done by programming the appropriate control
bits of the SSPCON and SSPSTAT registers. These
control bits allow the following to be specified:
• SCK as clock input
• Idle state of SCK (CKP bit)
• Data input sample phase (SMP bit)
• Output data on rising/falling edge of SCK (CKE bit)
Figure 17-4 and Figure 17-5 show example waveforms
of Slave mode operation.
Enabling Slave I/O
Slave Mode Setup
DS41341B-page 169