P89LPC938FA NXP Semiconductors, P89LPC938FA Datasheet - Page 17

• Manufacturer Part Number: P89LPC938FA
• Description: IC, MCU 8BIT 80C51 8K FLASH, PLCC28
• Manufacturer: NXP Semiconductors

Specifications of P89LPC938FA

• 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

Table 4:
* indicates SFRs that are bit addressable.
[1]
[2]
[3]
[4]
[5]
[6]
Name
WDL
WFEED1
WFEED2
BRGR1 and BRGR0 must only be written if BRGEN in BRGCON SFR is logic 0. If any are written while BRGEN = 1, the result is unpredictable.
All ports are in input only (high-impedance) state after power-up.
The RSTSRC register reflects the cause of the P89LPC938 reset. Upon a power-up reset, all reset source flags are cleared except POF and BOF; the power-on reset value is
xx110000.
The only reset source that affects these SFRs is power-on reset.
On power-on reset, the TRIM SFR is initialized with a factory preprogrammed value. Other resets will not cause initialization of the TRIM register.
After reset, the value is 111001x1, i.e., PRE2-PRE0 are all logic 1, WDRUN = 1 and WDCLK = 1. WDTOF bit is logic 1 after watchdog reset and is logic 0 after power-on reset.
Other resets will not affect WDTOF.
P89LPC938 Special function registers
Description
Watchdog load
Watchdog feed 1
Watchdog feed 2
SFR
addr.
C1H
C2H
C3H
Bit functions and addresses
…continued
MSB
LSB
Reset value
Hex
FF
Binary
11111111