p89lpc9351 NXP Semiconductors, p89lpc9351 Datasheet - Page 46

• Manufacturer Part Number: p89lpc9351
• Description: 8-bit Microcontroller With Accelerated Two-clock 80c51 Core 8 Kb 3 V Byte-erasable ?ash With 8-bit Adc
• Manufacturer: NXP Semiconductors

NXP Semiconductors
P89LPC9351_1
Preliminary data sheet
Fig 19. Watchdog timer in Watchdog mode (WDTE = 1)
watchdog
oscillator
(1) Watchdog reset can also be caused by an invalid feed sequence, or by writing to WDCON not immediately followed by a feed
PCLK
sequence.
7.29.1 Software reset
7.29.2 Dual data pointers
7.29.3 Data EEPROM
0
1
7.29 Additional features
MOV WFEED1, #0A5H
MOV WFEED2, #05AH
oscillator
external
crystal
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.
The P89LPC9351 has 512 bytes of on-chip Data EEPROM. The Data EEPROM is SFR
based, byte readable, byte writable, and erasable (via row fill and sector fill). The user can
read, write and fill the memory via SFRs and one interrupt. This Data EEPROM provides
100,000 minimum erase/program cycles for each byte.
•
•
•
XTALWD
0
1
Byte mode: In this mode, data can be read and written one byte at a time.
Row fill: In this mode, the addressed row (64 bytes) is filled with a single value. The
entire row can be erased by writing 00H.
Sector fill: In this mode, all 512 bytes are filled with a single value. The entire sector
can be erased by writing 00H.
WDCON (A7H)
32
PRE2
Rev. 01 — 19 November 2008
PRESCALER
PRE1
PRE0
SHADOW REGISTER
-
8-bit microcontroller with 8-bit ADC
-
8-BIT DOWN
WDL (C1H)
COUNTER
WDRUN
P89LPC9351
WDTOF
© NXP B.V. 2008. All rights reserved.
WDCLK
002aae015
reset
46 of 74
(1)