DSPIC30F5011-30I/PTG Microchip Technology, DSPIC30F5011-30I/PTG Datasheet - Page 87

• Manufacturer Part Number: DSPIC30F5011-30I/PTG
• Description: 16BIT MCU-DSP 30MHZ, SMD, 30F5011
• Manufacturer: Microchip Technology
• Series: DsPIC30Fr

Specifications of DSPIC30F5011-30I/PTG

• Core Frequency: 30MHz
• Embedded Interface Type: CAN, I2C, SPI, UART
• No. Of I/o's: 52
• Flash Memory Size: 66KB
• Supply Voltage Range: 2.5V To 5.5V
• Operating Temperature Range: -40°C To
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

14.0
The Serial Peripheral Interface (SPI) module is a syn-
chronous serial interface. It is useful for communicating
with other peripheral devices, such as EEPROMs, shift
registers, display drivers and A/D converters, or other
microcontrollers. It is compatible with Motorola's SPI
and SIOP interfaces.
14.1
Each SPI module consists of a 16-bit shift register,
SPIxSR (where x = 1 or 2), used for shifting data in and
out, and a buffer register, SPIxBUF. A control register,
SPIxCON, configures the module. Additionally, a status
register, SPIxSTAT, indicates various status conditions.
The serial interface consists of 4 pins: SDIx (serial data
input), SDOx (serial data output), SCKx (shift clock
input or output), and SSx (active low slave select).
In Master mode operation, SCK is a clock output but in
Slave mode, it is a clock input.
A series of eight (8) or sixteen (16) clock pulses shift
out bits from the SPIxSR to SDOx pin and simulta-
neously shift in data from SDIx pin. An interrupt is gen-
erated when the transfer is complete and the
corresponding interrupt flag bit (SPI1IF or SPI2IF) is
set. This interrupt can be disabled through an interrupt
enable bit (SPI1IE or SPI2IE).
The receive operation is double-buffered. When a com-
plete byte is received, it is transferred from SPIxSR to
SPIxBUF.
If the receive buffer is full when new data is being trans-
ferred from SPIxSR to SPIxBUF, the module will set the
SPIROV bit indicating an overflow condition. The trans-
fer of the data from SPIxSR to SPIxBUF will not be
completed and the new data will be lost. The module
will not respond to SCL transitions while SPIROV is ‘1’,
effectively disabling the module until SPIxBUF is read
by user software.
Transmit writes are also double-buffered. The user
writes to SPIxBUF. When the master or slave transfer
is completed, the contents of the shift register (SPIxSR)
are moved to the receive buffer. If any transmit data has
been written to the buffer register, the contents of the
transmit buffer are moved to SPIxSR. The received
data is thus placed in SPIxBUF and the transmit data in
SPIxSR is ready for the next transfer.
In Master mode, the clock is generated by prescaling
the system clock. Data is transmitted as soon as a
value is written to SPIxBUF. The interrupt is generated
at the middle of the transfer of the last bit.
 2004 Microchip Technology Inc.
Note:
SPI MODULE
Operating Function Description
Both the transmit buffer (SPIxTXB) and
the receive buffer (SPIxRXB) are mapped
to the same register address, SPIxBUF.
Preliminary
In Slave mode, data is transmitted and received as
external clock pulses appear on SCK. Again, the inter-
rupt is generated when the last bit is latched. If SSx
control is enabled, then transmission and reception are
enabled only when SSx = low. The SDOx output will be
disabled in SSx mode with SSx high.
The clock provided to the module is (F
clock is then prescaled by the primary (PPRE<1:0>)
and the secondary (SPRE<2:0>) prescale factors. The
CKE bit determines whether transmit occurs on transi-
tion from active clock state to Idle clock state, or vice
versa. The CKP bit selects the Idle state (high or low)
for the clock.
14.1.1
A control bit, MODE16 (SPIxCON<10>), allows the
module to communicate in either 16-bit or 8-bit mode.
16-bit operation is identical to 8-bit operation except
that the number of bits transmitted is 16 instead of 8.
The user software must disable the module prior to
changing the MODE16 bit. The SPI module is reset
when the MODE16 bit is changed by the user.
A basic difference between 8-bit and 16-bit operation is
that the data is transmitted out of bit 7 of the SPIxSR for
8-bit operation, and data is transmitted out of bit15 of
the SPIxSR for 16-bit operation. In both modes, data is
shifted into bit 0 of the SPIxSR.
14.1.2
A control bit, DISSDO, is provided to the SPIxCON reg-
ister to allow the SDOx output to be disabled. This will
allow the SPI module to be connected in an input only
configuration. SDO can also be used for general
purpose I/O.
14.2
The module supports a basic framed SPI protocol in
Master or Slave mode. The control bit FRMEN enables
framed SPI support and causes the SSx pin to perform
the frame synchronization pulse (FSYNC) function.
The control bit SPIFSD determines whether the SSx
pin is an input or an output (i.e., whether the module
receives or generates the frame synchronization
pulse). The frame pulse is an active high pulse for a
single SPI clock cycle. When frame synchronization is
enabled, the data transmission starts only on the
subsequent transmit edge of the SPI clock.
dsPIC30F5011/5013
Framed SPI Support
WORD AND BYTE
COMMUNICATION
SDOx DISABLE
DS70116C-page 85
OSC
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