NXP Semiconductors
P89LPC9321
8-bit microcontroller with accelerated two-clock 80C51 core
Since N ranges from 0 to 15, the CCLK frequency can be in the range of PCLK to
PCLK16.
7.22.9 CCU interrupts
There are seven interrupt sources on the CCU which share a common interrupt vector.
EA (IEN0.7)
ECCU (IEN1.4)
TOIE2 (TICR2.7)
TOIF2 (TIFR2.7)
TICIE2A (TICR2.0)
TICF2A (TIFR2.0)
TICIE2B (TICR2.1)
TICF2B (TIFR2.1)
TOCIE2A (TICR2.3)
TOCF2A (TIFR2.3)
TOCIE2B (TICR2.4)
TOCF2B (TIFR2.4)
TOCIE2C (TICR2.5)
TOCF2C (TIFR2.5)
TOCIE2D (TICR2.6)
TOCF2D (TIFR2.6)
other
interrupt
sources
PRIORITY
ENCODER
interrupt to
CPU
ENCINT.0
ENCINT.1
ENCINT.2
Fig 11. Capture/compare unit interrupts
002aaa896
7.23 UART
The P89LPC9321 has an enhanced UART that is compatible with the conventional 80C51
UART except that Timer 2 overflow cannot be used as a baud rate source. The
P89LPC9321 does include an independent baud rate generator. The baud rate can be
selected from the oscillator (divided by a constant), Timer 1 overflow, or the independent
baud rate generator. In addition to the baud rate generation, enhancements over the
standard 80C51 UART include Framing Error detection, automatic address recognition,
selectable double buffering and several interrupt options. The UART can be operated in
four modes: shift register, 8-bit UART, 9-bit UART, and CPU clock/32 or CPU clock/16.
7.23.1 Mode 0
Serial data enters and exits through RXD. TXD outputs the shift clock. 8 bits are
transmitted or received, LSB first. The baud rate is fixed at 1⁄16 of the CPU clock
frequency.
P89LPC9321_1
Product data sheet
Rev. 01 — 9 December 2008
© NXP B.V. 2008. All rights reserved.
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