PIC16C64A-04I/L Microchip Technology, PIC16C64A-04I/L Datasheet - Page 91

• Manufacturer Part Number: PIC16C64A-04I/L
• Description: IC MCU OTP 2KX14 PWM 44PLCC
• Manufacturer: Microchip Technology
• Series: PIC® 16Cr

Specifications of PIC16C64A-04I/L

• Core Size: 8-Bit
• Program Memory Size: 3.5KB (2K x 14)
• Core Processor: PIC
• Speed: 4MHz
• Connectivity: I²C, SPI
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 33
• Program Memory Type: OTP
• Ram Size: 128 x 8
• Voltage - Supply (vcc/vdd): 4 V ~ 6 V
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-PLCC
• Controller Family/series: PIC16C
• No. Of I/o's: 33
• Ram Memory Size: 128Byte
• Cpu Speed: 4MHz
• No. Of Timers: 3
• No. Of Pwm Channels: 1
• Embedded Interface Type: I2C, SPI
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: AC164309 - MODULE SKT FOR PM3 44PLCC444-1001 - DEMO BOARD FOR PICMICRO MCUDVA16XL441 - ADAPTER DEVICE ICE 44PLCC309-1040 - ADAPTER 44-PLCC ZIF TO 40-DIP309-1039 - ADAPTER 44-PLCC TO 40-DIPDV007003 - PROGRAMMER UNIVERSAL PROMATE II
• Eeprom Size: -
• Data Converters: -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant
• Other names: PIC16C64A-04I/LR; PIC16C64A-04I/LR

11.3.1
The SPI mode allows 8-bits of data to be synchro-
nously transmitted and received simultaneously. To
accomplish communication, typically three pins are
used:
• Serial Data Out (SDO) RC5/SDO
• Serial Data In (SDI) RC4/SDI/SDA
• Serial Clock (SCK) RC3/SCK/SCL
Additionally a fourth pin may be used when in a slave
mode of operation:
• Slave Select (SS) RA5/SS
When initializing the SPI, several options need to be
specified. This is done by programming the appropriate
control bits in the SSPCON register (SSPCON<5:0>)
and SSPSTAT<7:6>. These control bits allow the fol-
lowing to be specified:
• Master Mode (SCK is the clock output)
• Slave Mode (SCK is the clock input)
• Clock Polarity (Idle state of SCK)
• Clock edge (output data on rising/falling edge of
• Clock Rate (Master mode only)
• Slave Select Mode (Slave mode only)
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. Once the 8-bits of data
have been received, that byte is moved to the SSPBUF
register. Then
(SSPSTAT<0>) and interrupt flag bit SSPIF (PIR1<3>)
are set. This double buffering of the received data
(SSPBUF) allows the next byte to start reception before
reading the data that was just received. Any write to the
SSPBUF register during transmission/reception of data
will be ignored, and the write collision detect bit WCOL
(SSPCON<7>) will be set. User software must clear the
WCOL bit so that it can be determined if the following
write(s) to the SSPBUF register completed success-
fully. When the application software is expecting to
receive valid data, the SSPBUF should be read before
the next byte of data to transfer is written to the
SSPBUF. Buffer full bit BF (SSPSTAT<0>) indicates
when SSPBUF has been loaded with the received data
(transmission is complete). When the SSPBUF is read,
bit BF is cleared. This data may be irrelevant if the SPI
is only a transmitter. Generally the SSP Interrupt is
used to determine when the transmission/reception
has completed. The SSPBUF must be read and/or writ-
ten. If the interrupt method is not going to be used, then
software polling can be done to ensure that a write col-
lision does not occur. Example 11-2 shows the loading
of the SSPBUF (SSPSR) for data transmission. The
shaded instruction is only required if the received data
is meaningful.
1997 Microchip Technology Inc.
SCK)
SSP MODULE IN SPI MODE FOR
PIC16C66/67
the
buffer
Applicable Devices
61 62 62A R62 63 R63 64 64A R64 65 65A R65 66 67
full
detect
bit
BF
EXAMPLE 11-2: LOADING THE SSPBUF
LOOP BTFSS SSPSTAT, BF
The block diagram of the SSP module, when in SPI
mode (Figure 11-9), shows that the SSPSR is not
directly readable or writable, and can only be accessed
from addressing the SSPBUF register. Additionally, the
SSP status register (SSPSTAT) indicates the various
status conditions.
FIGURE 11-9: SSP BLOCK DIAGRAM
RC4/SDI/SDA
RC5/SDO
RC3/SCK/
SCL
RA5/SS
BCF
BSF
GOTO
BCF
MOVF
MOVWF RXDATA
MOVF
MOVWF SSPBUF
STATUS, RP1
STATUS, RP0
LOOP
STATUS, RP0
SSPBUF, W
TXDATA, W
Read
SS Control
Select
TRISC<3>
(SPI MODE)(PIC16C66/67)
Edge
Enable
SSPM3:SSPM0
bit0
Select
Edge
(SSPSR) REGISTER
(PIC16C66/67)
SSPBUF reg
SSPSR reg
Clock Select
PIC16C6X
4
;Specify Bank 1
;
;Has data been
;received
;(transmit
;complete)?
;No
;Specify Bank 0
;W reg = contents
; of SSPBUF
;Save in user RAM
;W reg = contents
; of TXDATA
;New data to xmit
2
DS30234D-page 91
Write
Prescaler
4, 16, 64
clock
shift
TMR2 output
data bus
Internal
2
T
CY