PIC16F74-I/L Microchip Technology Inc., PIC16F74-I/L Datasheet - Page 67

• Manufacturer Part Number: PIC16F74-I/L
• Description: 44 PIN, 7 KB FLASH, 192 RAM, 33 I/O
• Manufacturer: Microchip Technology Inc.

Specifications of PIC16F74-I/L

• A/d Inputs: 8-Channel, 8-Bit
• Cpu Speed: 5 MIPS
• Eeprom Memory: 0 Bytes
• Input Output: 33
• Interface: I2C/SPI/USART
• Memory Type: Flash
• Number Of Bits: 8
• Package Type: 44-pin PLCC
• Programmable Memory: 7K Bytes
• Ram Size: 192 Bytes
• Speed: 20 MHz
• Timers: 2-8-bit, 1-16-bit
• Voltage, Range: 2-5.5 V
• Lead Free Status / Rohs Status: RoHS Compliant part Electrostatic Device

9.3
The SSP module in I
functions, except general call support, and provides
interrupts on START and STOP bits in hardware to facil-
itate firmware implementations of the master functions.
The SSP module implements the standard mode speci-
fications as well as 7-bit and 10-bit addressing.
Two pins are used for data transfer. These are the RC3/
SCK/SCL pin, which is the clock (SCL), and the RC4/
SDI/SDA pin, which is the data (SDA). The user must
configure these pins as inputs or outputs through the
TRISC<4:3> bits.
The SSP module functions are enabled by setting SSP
enable bit SSPEN (SSPCON<5>).
FIGURE 9-5:
The SSP module has five registers for I
These are the:
• SSP Control Register (SSPCON)
• SSP Status Register (SSPSTAT)
• Serial Receive/Transmit Buffer (SSPBUF)
• SSP Shift Register (SSPSR) - Not directly accessible
• SSP Address Register (SSPADD)
 2002 Microchip Technology Inc.
RC3/SCK/SCL
RC4/
SDI/
SDA
SSP I
Read
Clock
2
Shift
C Operation
MSb
2
C mode, fully implements all slave
STOP bit Detect
SSP BLOCK DIAGRAM
(I
Match Detect
SSPADD reg
SSPBUF reg
START and
2
SSPSR reg
C MODE)
LSb
Write
(SSPSTAT reg)
Internal
Data Bus
2
Set, RESET
C operation.
S, P bits
Addr Match
The SSPCON register allows control of the I
tion. Four mode selection bits (SSPCON<3:0>) allow
one of the following I
• I
• I
• I
• I
• I
Selection of any I
forces the SCL and SDA pins to be open drain, pro-
vided these pins are programmed to inputs by setting
the appropriate TRISC bits. Pull-up resistors must be
provided externally to the SCL and SDA pins for proper
operation of the I
Additional information on SSP I
found in the PICmicro™ Mid-Range MCU Family Ref-
erence Manual (DS33023A).
9.3.1
In Slave mode, the SCL and SDA pins must be config-
ured as inputs (TRISC<4:3> set). The SSP module will
override the input state with the output data when
required (slave-transmitter).
When an address is matched, or the data transfer after
an address match is received, the hardware automati-
cally will generate the Acknowledge (ACK) pulse, and
then load the SSPBUF register with the received value
currently in the SSPSR register.
There are certain conditions that will cause the SSP
module not to give this ACK pulse. They include (either
or both):
a)
b)
In this case, the SSPSR register value is not loaded
into the SSPBUF, but bit SSPIF (PIR1<3>) is set.
Table 9-2 shows what happens when a data transfer
byte is received, given the status of bits BF and
SSPOV. The shaded cells show the condition where
user software did not properly clear the overflow condi-
tion. Flag bit BF is cleared by reading the SSPBUF reg-
ister, while bit SSPOV is cleared through software.
The SCL clock input must have a minimum high and
low for proper operation. The high and low times of the
I
SSP module, are shown in timing parameter #100 and
parameter #101.
2
C specification, as well as the requirements of the
STOP bit interrupts enabled to support Firmware
Master mode
STOP bit interrupts enabled to support Firmware
Master mode
support Firmware Master mode, Slave is IDLE
2
2
2
2
2
C Slave mode (7-bit address)
C Slave mode (10-bit address)
C Slave mode (7-bit address), with START and
C Slave mode (10-bit address), with START and
C START and STOP bit interrupts enabled to
The buffer full bit BF (SSPSTAT<0>) was set
before the transfer was received.
The overflow bit SSPOV (SSPCON<6>) was set
before the transfer was received.
SLAVE MODE
2
C module.
2
C mode with the SSPEN bit set,
2
C modes to be selected:
PIC16F7X
2
C operation can be
DS30325B-page 65
2
C opera-