P89V662FBC,557 NXP Semiconductors, P89V662FBC,557 Datasheet - Page 47

• Manufacturer Part Number: P89V662FBC,557
• Description: IC 80C51 MCU FLASH 32K 44-TQFP
• Manufacturer: NXP Semiconductors
• Series: 89Vr

Specifications of P89V662FBC,557

• Program Memory Type: FLASH
• Program Memory Size: 32KB (32K x 8)
• Package / Case: 44-TQFP
• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 40MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: POR, PWM, WDT
• Number Of I /o: 36
• Ram Size: 1K x 8
• Voltage - Supply (vcc/vdd): 4.5 V ~ 5.5 V
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Processor Series: P89V6x
• Core: 80C51
• Data Bus Width: 8 bit
• Data Ram Size: 1 KB
• Interface Type: I2C/UART
• Maximum Clock Frequency: 40 MHz
• Number Of Programmable I/os: 36
• Number Of Timers: 3
• Operating Supply Voltage: 4.5 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: PK51, CA51, A51, ULINK2
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: 622-1001 - USB IN-CIRCUIT PROG 80C51ISP
• Eeprom Size: -
• Data Converters: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 568-2435; 935280832557; P89V662FBC

NXP Semiconductors
P89V660_662_664_3
Product data sheet
6.6.4 Baud rate generator mode
Bits TCLK and/or RCLK in T2CON allow the UART) transmit and receive baud rates to be
derived from either Timer 1 or Timer 2 (See
Timer 1 is used as the UART transmit baud rate generator. When TCLK = 1, Timer 2 is
used as the UART transmit baud rate generator. RCLK has the same effect for the UART
receive baud rate. With these two bits, the serial port can have different receive and
transmit baud rates – Timer 1 or Timer 2.
Figure 21
The baud rate generation mode is like the auto-reload mode, when a rollover in TH2
causes the Timer 2 registers to be reloaded with the 16-bit value in registers RCAP2H and
RCAP2L, which are preset by software.
The baud rates in modes 1 and 3 are determined by Timer 2’s overflow rate given below:
The timer can be configured for either ‘timer’ or ‘counter’ operation. In many applications,
it is configured for ‘timer' operation (C/T2 = 0). Timer operation is different for Timer 2
when it is being used as a baud rate generator.
Usually, as a timer it would increment every machine cycle (i.e.,
frequency). As a baud rate generator, it increments at the oscillator frequency. Thus the
baud rate formula is as follows:
Where: (RCAP2H, RCAP2L) = The content of RCAP2H and RCAP2L taken as a 16-bit
unsigned integer.
The Timer 2 as a baud rate generator mode is valid only if RCLK and/or TCLK = 1 in
T2CON register. Note that a rollover in TH2 does not set TF2, and will not generate an
interrupt. Thus, the Timer 2 interrupt does not have to be disabled when Timer 2 is in the
----------------------------------------------------------------------------------------------- -
16
Fig 21. Timer 2 in Baud Rate Generator mode
Modes 1 and 3 Baud Rates = Timer 2 Overflow Rate / 16
Modes 1 and 3 Baud Rates =
T2 pin
OSC
65536 RCAP2H RCAP2L
OscillatorFrequency
shows Timer 2 in baud rate generator mode:
T2EX pin
–
2
transition
detector
Rev. 03 — 10 November 2008
C/T2 = 0
C/T2 = 1
EXEN2
80C51 with 512 B/1 kB/2 kB RAM, dual I
control
TR2
control
Section 6.7
EXF2
RCAP2L RCAP2H
(8-bits)
timer 2
interrupt
P89V660/662/664
TL2
for details). When TCLK = 0,
(8-bits)
TH2
reload
1
6
the oscillator
© NXP B.V. 2008. All rights reserved.
TX/RX baud rate
002aaa526
2
C-bus, SPI
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