P89LPC931FDH,112 NXP Semiconductors, P89LPC931FDH,112 Datasheet - Page 37

• Manufacturer Part Number: P89LPC931FDH,112
• Description: IC 80C51 MCU FLASH 8K 28-TSSOP
• Manufacturer: NXP Semiconductors
• Series: LPC900r

Specifications of P89LPC931FDH,112

• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 12MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, LED, POR, PWM, WDT
• Number Of I /o: 26
• Program Memory Size: 8KB (8K x 8)
• Program Memory Type: FLASH
• Ram Size: 256 x 8
• Voltage - Supply (vcc/vdd): 2.4 V ~ 3.6 V
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 28-TSSOP
• Processor Series: P89LPC9x
• Core: 80C51
• Data Bus Width: 8 bit
• Data Ram Size: 256 B
• Interface Type: I2C, SPI, UART
• Maximum Clock Frequency: 18 MHz
• Number Of Programmable I/os: 26
• Number Of Timers: 2
• Operating Supply Voltage: 2.4 V to 3.6 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: PK51, CA51, A51, ULINK2
• Minimum Operating Temperature: - 45 C
• For Use With: 622-1014 - BOARD FOR LPC9XX TSSOP622-1008 - BOARD FOR LPC9103 10-HVSON622-1006 - SOCKET ADAPTER BOARDMCB900K - BOARD PROTOTYPE NXP 89LPC9EPM900K - EMULATOR/PROGRAMMER NXP P89LPC9568-4000 - DEMO BOARD SPI/I2C TO DUAL UART568-3510 - DEMO BOARD SPI/I2C TO UART622-1002 - USB IN-CIRCUIT PROG LPC9XX568-1759 - EMULATOR DEBUGGER/PROGRMMR LPC9X568-1758 - BOARD EVAL FOR LPC93X MCU FAMILY
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Data Converters: -
• Lead Free Status / Rohs Status: Details
• Other names: 568-1284-5; 935273877112; P89LPC931FDH; P89LPC931FDH,129; P89LPC931FDH-S

Philips Semiconductors
9397 750 14472
Product data
Fig 14. Watchdog timer in Watchdog mode (WDTE = ‘1’).
(1) Watchdog reset can also be caused by an invalid feed sequence, or by writing to WDCON not immediately followed by a
Watchdog
oscillator
feed sequence.
MOV WFEED1, #0A5H
MOV WFEED2, #05AH
PCLK
8.23.1 Software reset
8.23.2 Dual data pointers
8.22 Watchdog timer
8.23 Additional features
WDCON (A7H)
32
The watchdog timer causes a system reset when it underflows as a result of a failure
to feed the timer prior to the timer reaching its terminal count. It consists of a
programmable 12-bit prescaler, and an 8-bit down counter. The down counter is
decremented by a tap taken from the prescaler. The clock source for the prescaler is
either the PCLK or the nominal 400 kHz Watchdog oscillator. The watchdog timer can
only be reset by a power-on reset. When the Watchdog feature is disabled, it can be
used as an interval timer and may generate an interrupt.
watchdog timer in Watchdog mode. Feeding the watchdog requires a two-byte
sequence. If PCLK is selected as the Watchdog clock and the CPU is powered-down,
the watchdog is disabled. The watchdog timer has a time-out period that ranges from
a few s to a few seconds. Please refer to the P89LPC930/931 User’s Manual for
more details.
The SRST bit in AUXR1 gives software the opportunity to reset the processor
completely, as if an external reset or Watchdog reset had occurred. Care should be
taken when writing to AUXR1 to avoid accidental software resets.
The dual Data Pointers (DPTR) provides two different Data Pointers to specify the
address used with certain instructions. The DPS bit in the AUXR1 register selects
one of the two Data Pointers. Bit 2 of AUXR1 is permanently wired as a logic ‘0’ so
that the DPS bit may be toggled (thereby switching Data Pointers) simply by
incrementing the AUXR1 register, without the possibility of inadvertently altering other
bits in the register.
PRE2
PRESCALER
PRE1
Rev. 05 — 15 December 2004
CONTROL REGISTER
PRE0
–
8-bit microcontrollers with two-clock 80C51 core
–
8-BIT DOWN
WDL (C1H)
COUNTER
WDRUN
WDTOF
P89LPC930/931
© Koninklijke Philips Electronics N.V. 2004. All rights reserved.
Figure 14
WDCLK
002aaa423
RESET
see note (1)
shows the
SHADOW
REGISTER
FOR WDCON
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