P89LPC912FDH NXP Semiconductors, P89LPC912FDH Datasheet - Page 38

• Manufacturer Part Number: P89LPC912FDH
• Description: MCU 8BIT 80C51 1K FLASH, TSSOP14
• Manufacturer: NXP Semiconductors

Specifications of P89LPC912FDH

• Controller Family/series: (8051) 8052
• Core Size: 8bit
• No. Of I/o's: 12
• Program Memory Size: 1KB
• Ram Memory Size: 128Byte
• Cpu Speed: 18MHz
• Oscillator Type: External, Internal
• No. Of Timers: 4
• No. Of: RoHS Compliant

NXP Semiconductors
P89LPC912_913_914_5
Product data sheet
8.16.1 Mode 0
8.16.2 Mode 1
8.16.3 Mode 2
8.16 Timers/counters 0 and 1
Reset can be triggered from the following sources:
For every reset source, there is a flag in the Reset Register, RSTSRC. The user can read
this register to determine the most recent reset source. These flag bits can be cleared in
software by writing a logic 0 to the corresponding bit. More than one flag bit may be set:
The P89LPC912/913/914 devices have two general purpose counter/timers which are
upward compatible with the standard 80C51 Timer 0 and Timer 1. An option to
automatically toggle the T0 pin upon timer overflow has been added (P89LPC912,
P89LPC914). In the ‘Timer’ function, the register is incremented every machine cycle. In
the ‘Counter’ function, the register of Timer 0 is incremented in response to a 1-to-0
transition at its external input pin, T0. This external input is sampled once very machine
cycle.
Timer 0 has four operating modes (modes 0, 1, 2, and 3) on the P89LPC913).
Timer 0 has five operating modes (modes 0, 1, 2, 3, and 6 on the P89LPC912 and
P89LPC914.
Timer 1 has four operating modes (modes 0, 1, 2, and 3) on all devices. Modes 0, 1, and 2
are the same for both Timers/Counters. Mode 3 is different.
Putting either Timer into Mode 0 makes it look like an 8048 Timer, which is an 8-bit
Counter with a divide-by-32 prescaler. In this mode, the Timer register is configured as a
13-bit register. Mode 0 operation is the same for Timer 0 and Timer 1.
Mode 1 is the same as Mode 0, except that all 16 bits of the timer register are used.
Mode 2 configures the Timer register as an 8-bit Counter with automatic reload. Mode 2
operation is the same for Timer 0 and Timer 1.
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External reset pin (during power-up or if user configured via UCFG1. This option must
be used for an oscillator frequency above 12 MHz.)
Power-on detect
Brownout detect
Watchdog timer
Software reset
UART break character detect reset (P89LPC913, P89LPC914).
During a power-on reset, both POF and BOF are set but the other flag bits are
cleared.
For any other reset, previously set flag bits that have not been cleared will remain set.
Rev. 05 — 28 September 2007
8-bit microcontrollers with two-clock 80C51 core
P89LPC912/913/914
© NXP B.V. 2007. All rights reserved.
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