P89LPC938FDH NXP Semiconductors, P89LPC938FDH Datasheet - Page 22

• Manufacturer Part Number: P89LPC938FDH
• Description: MCU 8BIT 80C51 8K FLASH, TSSOP28
• Manufacturer: NXP Semiconductors

Specifications of P89LPC938FDH

• Controller Family/series: (8051) 8052
• Core Size: 8bit
• No. Of I/o's: 26
• Program Memory Size: 8KB
• Eeprom Memory Size: 512Byte
• Ram Memory Size: 768Byte
• Cpu Speed: 18MHz
• Oscillator Type: External,
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Philips Semiconductors
9397 750 14051
Product data sheet
7.12.1 External interrupt inputs
7.11 Data RAM arrangement
7.12 Interrupts
The P89LPC938 also has 512 bytes of on-chip Data EEPROM that is accessed via SFRs
(see
The 768 bytes of on-chip RAM are organized as shown in
Table 6:
The P89LPC938 uses a four priority level interrupt structure. This allows great flexibility in
controlling the handling of the many interrupt sources. The P89LPC938 supports
15 interrupt sources: external interrupts 0 and 1, timers 0 and 1, serial port Tx, serial port
Rx, combined serial port Rx/Tx, brownout detect, watchdog/RTC, I
comparators 1 and 2, SPI, CCU, data EEPROM write/ADC completion.
Each interrupt source can be individually enabled or disabled by setting or clearing a bit in
the interrupt enable registers IEN0 or IEN1. The IEN0 register also contains a global
disable bit, EA, which disables all interrupts.
Each interrupt source can be individually programmed to one of four priority levels by
setting or clearing bits in the interrupt priority registers IP0, IP0H, IP1, and IP1H. An
interrupt service routine in progress can be interrupted by a higher priority interrupt, but
not by another interrupt of the same or lower priority. The highest priority interrupt service
cannot be interrupted by any other interrupt source. If two requests of different priority
levels are pending at the start of an instruction, the request of higher priority level is
serviced.
If requests of the same priority level are pending at the start of an instruction, an internal
polling sequence determines which request is serviced. This is called the arbitration
ranking. Note that the arbitration ranking is only used to resolve pending requests of the
same priority level.
The P89LPC938 has two external interrupt inputs as well as the Keypad Interrupt function.
The two interrupt inputs are identical to those present on the standard 80C51
microcontrollers.
These external interrupts can be programmed to be level-triggered or edge-triggered by
setting or clearing bit IT1 or IT0 in Register TCON.
Type
DATA
IDATA
XDATA
•
CODE
64 kB of Code memory space, accessed as part of program execution and via the
MOVC instruction. The P89LPC938 has 8 kB of on-chip Code memory.
Section 7.27 “Data
On-chip data memory usages
Data RAM
Memory that can be addressed directly and indirectly
Memory that can be addressed indirectly
Auxiliary (‘External Data’) on-chip memory that is accessed
using the MOVX instructions
Rev. 01 — 25 February 2005
EEPROM”).
8-bit microcontroller with 10-bit A/D converter
Table
© Koninklijke Philips Electronics N.V. 2005. All rights reserved.
6.
P89LPC938
2
C, keyboard,
Size (bytes)
128
256
512
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