PIC16C765-I/PT Microchip Technology, PIC16C765-I/PT Datasheet - Page 81

• Manufacturer Part Number: PIC16C765-I/PT
• Description: IC,MICROCONTROLLER,8-BIT,PIC CPU,CMOS,TQFP,44PIN,PLASTIC
• Manufacturer: Microchip Technology
• Series: PIC® 16Cr

Specifications of PIC16C765-I/PT

• Rohs Compliant: YES
• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 24MHz
• Connectivity: SCI, UART/USART, USB
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 33
• Program Memory Size: 14KB (8K x 14)
• Program Memory Type: OTP
• Ram Size: 256 x 8
• Voltage - Supply (vcc/vdd): 4.35 V ~ 5.25 V
• Data Converters: A/D 8x8b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-TQFP, 44-VQFP
• Processor Series: PIC16C
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 256 B
• Maximum Clock Frequency: 24 MHz
• Number Of Programmable I/os: 33
• Number Of Timers: 3 bit
• Operating Supply Voltage: 4.35 V to 5.25 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: 52715-96, 52716-328, 52717-734
• Development Tools By Supplier: ICE2000, DM163022
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 8 bit
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: XLT44PT3 - SOCKET TRAN ICE 44MQFP/TQFPAC164305 - MODULE SKT FOR PM3 44TQFPISPICR1 - ADAPTER IN-CIRCUIT PROGRAMMING444-1001 - DEMO BOARD FOR PICMICRO MCUAC164020 - MODULE SKT PROMATEII 44TQFP
• Eeprom Size: -
• Lead Free Status / Rohs Status: Details

11.2
In this mode, the USART uses standard nonreturn-to-
zero (NRZ) format (one start bit, eight or nine data bits,
and one stop bit). The most common data format is 8
bits. An on-chip, dedicated, 8-bit baud rate generator
can be used to derive standard baud rate frequencies
from the oscillator. The USART transmits and receives
the LSb first. The USART’s transmitter and receiver are
functionally independent, but use the same data format
and baud rate. The baud rate generator produces a
clock either x16 or x64 of the bit shift rate, depending
on bit BRGH (TXSTA<2>). Parity is not supported by
the hardware, but can be implemented in software (and
stored as the ninth data bit). Asynchronous mode is
stopped during SLEEP.
Asynchronous mode is selected by clearing bit SYNC
(TXSTA<4>).
The USART Asynchronous module consists of the fol-
lowing important elements:
• Baud Rate Generator
• Sampling Circuit
• Asynchronous Transmitter
• Asynchronous Receiver
11.2.1
The USART transmitter block diagram is shown in
Figure 11-1. The heart of the transmitter is the transmit
(serial) shift register (TSR). The shift register obtains its
data from the read/write transmit buffer, TXREG. The
TXREG register is loaded with data in software. The
TSR register is not loaded until the STOP bit has been
transmitted from the previous load. As soon as the
STOP bit is transmitted, the TSR is loaded with new
data from the TXREG register (if available). Once the
TXREG register transfers the data to the TSR register
(occurs in one T
flag bit TXIF (PIR1<4>) is set. This interrupt can be
enabled/disabled by setting/clearing enable bit TXIE
FIGURE 11-1: USART TRANSMIT BLOCK DIAGRAM
2000 Microchip Technology Inc.
USART Asynchronous Mode
USART ASYNCHRONOUS TRANSMITTER
TXIE
CY
Interrupt
), the TXREG register is empty and
TXIF
TXEN
Baud Rate Generator
SPBRG
Baud Rate CLK
MSb
(8)
TX9D
Preliminary
TSR Register
TX9
TXREG Register
8
Data Bus
( PIE1<4>). Flag bit TXIF will be set regardless of the
state of enable bit TXIE and cannot be cleared in soft-
ware. It will reset only when new data is loaded into the
TXREG register. While flag bit TXIF indicated the sta-
tus of the TXREG register, another bit TRMT
(TXSTA<1>) shows the status of the TSR register. Sta-
tus bit TRMT is a read only bit, which is set when the
TSR register is empty. No interrupt logic is tied to this
bit, so the user has to poll this bit in order to determine
if the TSR register is empty.
Transmission is enabled by setting enable bit TXEN
(TXSTA<5>). The actual transmission will not occur
until the TXREG register has been loaded with data
and the baud rate generator (BRG) has produced a
shift clock (Figure 11-2). The transmission can also be
started by first loading the TXREG register and then
setting enable bit TXEN. Normally, when transmission
is first started, the TSR register is empty. At that point,
transfer to the TXREG register will result in an immedi-
ate transfer to TSR, resulting in an empty TXREG. A
back-to-back transfer is thus possible (Figure 11-3).
Clearing enable bit TXEN during a transmission will
cause the transmission to be aborted and will reset the
transmitter. As a result, the RC6/TX/CK pin will revert
to hi-impedance.
In order to select 9-bit transmission, transmit bit TX9
(TXSTA<6>) should be set and the ninth bit should be
written to TX9D (TXSTA<0>). The ninth bit must be
written before writing the 8-bit data to the TXREG reg-
ister. This is because a data write to the TXREG regis-
ter can result in an immediate transfer of the data to the
TSR register (if the TSR is empty). In such a case, an
incorrect ninth data bit may be loaded in the TSR
register.
Note 1: The TSR register is not mapped in data
LSb
2: Flag bit TXIF is set when enable bit TXEN
0
memory, so it is not available to the user.
is set. TXIF is cleared by loading TXREG.
TRMT
PIC16C745/765
Pin Buffer
and Control
SPEN
RC6/TX/CK pin
DS41124C-page 81