PIC16F874-20/L Microchip Technology, PIC16F874-20/L Datasheet - Page 271

• Manufacturer Part Number: PIC16F874-20/L
• Description: IC MCU FLASH 4KX14 EE 44PLCC
• Manufacturer: Microchip Technology
• Series: PIC® 16Fr

Specifications of PIC16F874-20/L

• Core Size: 8-Bit
• Program Memory Size: 7KB (4K x 14)
• Core Processor: PIC
• Speed: 20MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 33
• Program Memory Type: FLASH
• Eeprom Size: 128 x 8
• Ram Size: 192 x 8
• Voltage - Supply (vcc/vdd): 4 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: External
• Operating Temperature: 0°C ~ 70°C
• Package / Case: 44-PLCC
• Controller Family/series: PIC16F
• No. Of I/o's: 33
• Eeprom Memory Size: 128Byte
• Ram Memory Size: 192Byte
• Cpu Speed: 20MHz
• No. Of Timers: 3
• Processor Series: PIC16F
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 192 B
• Interface Type: MSSP, PSP, USART
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 33
• Number Of Timers: 3
• Operating Supply Voltage: 2 V to 5.5 V
• Maximum Operating Temperature: + 70 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: 52715-96, 52716-328, 52717-734
• Development Tools By Supplier: PG164130, DV164035, DV244005, DV164005, PG164120, ICE2000, DM163022, DV164120
• Minimum Operating Temperature: 0 C
• On-chip Adc: 10 bit, 8 Channel
• 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
• Lead Free Status / Rohs Status: Details

16.4.2
16.4.3
1997 Microchip Technology Inc.
Master Mode (Firmware)
Multi-Master Mode (Firmware)
Master mode of operation is supported by interrupt generation on the detection of the START and
STOP conditions. The STOP (P) and START (S) bits are cleared from a reset or when the SSP
module is disabled. Control of the I
with both the S and P bits clear.
In master mode the SCL and SDA lines are manipulated by clearing the corresponding TRIS
bit(s). The output level is always low, irrespective of the value(s) in PORT. So when transmitting
data, a '1' data bit must have the TRIS bit set (input) and a '0' data bit must have the TRIS bit
cleared (output). The same scenario is true for the SCL line with the TRIS bit.
The following events will cause the SSPIF Interrupt Flag bit to be set (SSP Interrupt if enabled):
• START condition
• STOP condition
• Data transfer byte transmitted/received
Master mode of operation can be done with either the slave mode idle (SSPM3:SSPM0 = 1011)
or with the slave active (SSPM3:SSP0 = 1110 or 1111). When the slave modes are enabled, the
software needs to differentiate the source(s) of the interrupt.
In multi-master mode, the interrupt generation on the detection of the START and STOP condi-
tions allows the determination of when the bus is free. The STOP (P) and START (S) bits are
cleared from a reset or when the SSP module is disabled. Control of the I
when the P bit (SSPSTAT<4>) is set, or the bus is idle with both the S and P bits clear. When the
bus is busy, enabling the SSP Interrupt will generate the interrupt when the STOP condition
occurs.
In multi-master operation, the SDA line must be monitored to see if the signal level is the
expected output level. This check only needs to be done when a high level is output. If a high level
is expected and a low level is present, the device needs to release the SDA and SCL lines (set
the TRIS bits). There are two stages where this arbitration can be lost, they are:
• Address Transfer
• Data Transfer
When the slave logic is enabled, the slave continues to receive. If arbitration was lost during the
address transfer stage, communication to the device may be in progress. If addressed an ACK
pulse will be generated. If arbitration was lost during the data transfer stage, the device will need
to re-transfer the data at a later time.
2
C bus may be taken when the P bit is set, or the bus is idle
Section 16. BSSP
2
DS31016A-page 16-21
C bus may be taken
16