PIC18F2420-I/ML Microchip Technology, PIC18F2420-I/ML Datasheet - Page 176

• Manufacturer Part Number: PIC18F2420-I/ML
• Description: IC PIC MCU FLASH 8KX16 28QFN
• Manufacturer: Microchip Technology
• Series: PIC® 18Fr

Specifications of PIC18F2420-I/ML

• Program Memory Type: FLASH
• Program Memory Size: 16KB (8K x 16)
• Package / Case: 28-VQFN Exposed Pad, 28-HVQFN, 28-SQFN, 28-DHVQFN
• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 40MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, HLVD, POR, PWM, WDT
• Number Of I /o: 25
• Eeprom Size: 256 x 8
• Ram Size: 768 x 8
• Voltage - Supply (vcc/vdd): 4.2 V ~ 5.5 V
• Data Converters: A/D 10x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Processor Series: PIC18F
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 768 B
• Interface Type: EUSART, I2C, MSSP, SPI
• Maximum Clock Frequency: 40 MHz
• Number Of Programmable I/os: 25
• Number Of Timers: 1 x 8
• Operating Supply Voltage: 2 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: 52715-96, 52716-328, 52717-734, 52712-325, EWPIC18
• Development Tools By Supplier: PG164130, DV164035, DV244005, DV164005, PG164120, ICE2000, ICE4000, DM163014, DV164136
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit
• Package: 28QFN EP
• Device Core: PIC
• Family Name: PIC18
• Maximum Speed: 40 MHz
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: XLT28QFN4 - SOCKET TRANS ICE 28QFN W/CABLEAC164322 - MODULE SOCKET MPLAB PM3 28/44QFN
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

PIC18F2420/2520/4420/4520
17.4.2
The MSSP module functions are enabled by setting the
MSSP Enable bit, SSPEN (SSPCON1<5>).
The SSPCON1 register allows control of the I
operation. Four mode selection bits (SSPCON1<3:0>)
allow one of the following I
• I
• I
• I
• I
• I
• I
Selection of any I
forces the SCL and SDA pins to be open-drain,
provided these pins are programmed to inputs by
setting the appropriate TRISC bits. To ensure proper
operation of the module, pull-up resistors must be
provided externally to the SCL and SDA pins.
17.4.3
In Slave mode, the SCL and SDA pins must be config-
ured as inputs (TRISC<4:3> set). The MSSP module
will override the input state with the output data when
required (slave-transmitter).
The I
interrupt on an address match. Through the mode
select bits, the user can also choose to interrupt on
Start and Stop bits
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
load the SSPBUF register with the received value
currently in the SSPSR register.
Any combination of the following conditions will cause
the MSSP module not to give this ACK pulse:
• The Buffer Full bit, BF (SSPSTAT<0>), was set
• The overflow bit, SSPOV (SSPCON2<6>), was
In this case, the SSPSR register value is not loaded
into the SSPBUF, but bit, SSPIF (PIR1<3>), is set. The
BF bit is cleared by reading the SSPBUF register, 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
MSSP module, are shown in timing parameter 100 and
parameter 101.
DS39631E-page 174
2
C specification, as well as the requirement of the
Stop bit interrupts enabled
Stop bit interrupts enabled
Idle
before the transfer was received.
set before the transfer was received.
2
2
2
2
2
2
C Master mode, clock = (F
C Slave mode (7-bit addressing)
C Slave mode (10-bit addressing)
C Slave mode (7-bit addressing) with Start and
C Slave mode (10-bit addressing) with Start and
C Firmware Controlled Master mode, slave is
2
C Slave mode hardware will always generate an
OPERATION
SLAVE MODE
2
C mode, with the SSPEN bit set,
2
C modes to be selected:
OSC
/4) x (SSPADD + 1)
2
C
17.4.3.1
Once the MSSP module has been enabled, it waits for
a Start condition to occur. Following the Start condition,
the 8 bits are shifted into the SSPSR register. All
incoming bits are sampled with the rising edge of the
clock (SCL) line. The value of register SSPSR<7:1> is
compared to the value of the SSPADD register. The
address is compared on the falling edge of the eighth
clock (SCL) pulse. If the addresses match and the BF
and SSPOV bits are clear, the following events occur:
1.
2.
3.
4.
In 10-Bit Addressing mode, two address bytes need to
be received by the slave. The five Most Significant bits
(MSbs) of the first address byte specify if this is a 10-bit
address. Bit, R/W (SSPSTAT<2>), must specify a write
so the slave device will receive the second address
byte. For a 10-bit address, the first byte would
equal ‘11110 A9 A8 0’, where ‘A9’ and ‘A8’ are the
two MSbs of the address. The sequence of events for
10-Bit Addressing mode is as follows, with steps 7
through 9 for the slave-transmitter:
1.
2.
3.
4.
5.
6.
7.
8.
9.
The SSPSR register value is loaded into the
SSPBUF register.
The Buffer Full bit, BF, is set.
An ACK pulse is generated.
MSSP Interrupt Flag bit, SSPIF (PIR1<3>), is
set (interrupt is generated, if enabled) on the
falling edge of the ninth SCL pulse.
Receive first (high) byte of address (bits, SSPIF,
BF and UA (SSPSTAT<1>), are set).
Update the SSPADD register with second (low)
byte of address (clears UA bit and releases the
SCL line).
Read the SSPBUF register (clears BF bit) and
clear flag bit, SSPIF.
Receive second (low) byte of address (bits,
SSPIF, BF and UA, are set).
Update the SSPADD register with the first (high)
byte of address. If match releases SCL line, this
will clear bit, UA.
Read the SSPBUF register (clears BF bit) and
clear flag bit, SSPIF.
Receive Repeated Start condition.
Receive first (high) byte of address (bits, SSPIF
and BF, are set).
Read the SSPBUF register (clears BF bit) and
clear flag bit, SSPIF.
Addressing
© 2008 Microchip Technology Inc.