P89LPC938FDH,529 NXP Semiconductors, P89LPC938FDH,529 Datasheet - Page 34

• Manufacturer Part Number: P89LPC938FDH,529
• Description: IC 80C51 MCU FLASH 8K 28-TSSOP
• Manufacturer: NXP Semiconductors
• Series: LPC900r

Specifications of P89LPC938FDH,529

• Program Memory Type: FLASH
• Program Memory Size: 8KB (8K x 8)
• Package / Case: 28-TSSOP
• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 18MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, LED, POR, PWM, WDT
• Number Of I /o: 26
• Eeprom Size: 512 x 8
• Ram Size: 768 x 8
• Voltage - Supply (vcc/vdd): 2.4 V ~ 3.6 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Processor Series: P89LPC9x
• Core: 80C51
• Data Bus Width: 8 bit
• Data Ram Size: 256 B
• Interface Type: I2C/SPI/UART
• Maximum Clock Frequency: 18 MHz
• Number Of Programmable I/os: 26
• Number Of Timers: 2
• Operating Supply Voltage: 2.4 V to 3.6 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: PK51, CA51, A51, ULINK2
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 8-ch x 10-bit
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: 622-1014 - BOARD FOR LPC9XX TSSOP622-1011 - BOARD FOR LPC938 TSSOP622-1008 - BOARD FOR LPC9103 10-HVSON622-1006 - SOCKET ADAPTER BOARDMCB900K - BOARD PROTOTYPE NXP 89LPC9EPM900K - EMULATOR/PROGRAMMER NXP P89LPC9568-4000 - DEMO BOARD SPI/I2C TO DUAL UART568-3510 - DEMO BOARD SPI/I2C TO UART568-1759 - EMULATOR DEBUGGER/PROGRMMR LPC9X568-1758 - BOARD EVAL FOR LPC93X MCU FAMILY
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 568-2013-5; 935278546529; P89LPC938FDH-S

Philips Semiconductors
9397 750 14051
Product data sheet
7.20.10 The 9
7.20.8 Double buffering
7.20.9 Transmit interrupts with double buffering enabled (Modes 1, 2 and 3)
The UART has a transmit double buffer that allows buffering of the next character to be
written to SBUF while the first character is being transmitted. Double buffering allows
transmission of a string of characters with only one stop bit between any two characters,
as long as the next character is written between the start bit and the stop bit of the
previous character.
Double buffering can be disabled. If disabled (DBMOD, i.e., SSTAT.7 = 0), the UART is
compatible with the conventional 80C51 UART. If enabled, the UART allows writing to
SnBUF while the previous data is being shifted out. Double buffering is only allowed in
Modes 1, 2 and 3. When operated in Mode 0, double buffering must be disabled
(DBMOD = 0).
Unlike the conventional UART, in double buffering mode, the Tx interrupt is generated
when the double buffer is ready to receive new data.
If double buffering is disabled TB8 can be written before or after SBUF is written, as long
as TB8 is updated some time before that bit is shifted out. TB8 must not be changed until
the bit is shifted out, as indicated by the Tx interrupt.
If double buffering is enabled, TB8 must be updated before SBUF is written, as TB8 will
be double-buffered together with SBUF data.
th
bit (bit 8) in double buffering (Modes 1, 2 and 3)
Rev. 01 — 25 February 2005
8-bit microcontroller with 10-bit A/D converter
© Koninklijke Philips Electronics N.V. 2005. All rights reserved.
P89LPC938
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