AT89C5131A-S3SUL Atmel, AT89C5131A-S3SUL Datasheet - Page 66

• Manufacturer Part Number: AT89C5131A-S3SUL
• Description: MCU 8051 32K FLASH USB 52-PLCC
• Manufacturer: Atmel
• Series: AT89C513xr

Specifications of AT89C5131A-S3SUL

• Core Processor: C52X2
• Core Size: 8-Bit
• Speed: 48MHz
• Connectivity: I²C, SPI, UART/USART, USB
• Peripherals: LED, POR, PWM, WDT
• Number Of I /o: 34
• Program Memory Size: 32KB (32K x 8)
• Program Memory Type: FLASH
• Eeprom Size: 4K x 8
• Ram Size: 1.25K x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 3.6 V
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 52-PLCC
• Processor Series: AT89x
• Core: 8051
• Data Bus Width: 8 bit
• Data Ram Size: 1.25 KB
• Interface Type: 2-Wire, EUART, SPI, USB
• Maximum Clock Frequency: 48 MHz
• Number Of Programmable I/os: 34
• Number Of Timers: 3 bit
• Operating Supply Voltage: 3 V to 3.6 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: PK51, CA51, A51, ULINK2
• Development Tools By Supplier: AT89STK-05
• Minimum Operating Temperature: - 40 C
• For Use With: AT89STK-10 - KIT EVAL APPL MASS STORAGEAT89STK-05 - KIT STARTER FOR AT89C5131
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Data Converters: -
• Lead Free Status / Rohs Status: Details

Serial I/O Port
Framing Error Detection
66
AT89C5131A-L
The serial I/O port in the AT89C5131A-L is compatible with the serial I/O port in the
80C52.
It provides both synchronous and asynchronous communication modes. It operates as
an Universal Asynchronous Receiver and Transmitter (UART) in three full-duplex
modes (modes 1, 2 and 3). Asynchronous transmission and reception can occur simul-
taneously and at different baud rates.
Serial I/O port includes the following enhancements:
•
•
Framing bit error detection is provided for the three asynchronous modes (modes 1, 2
and 3). To enable the framing bit error detection feature, set SMOD0 bit in PCON regis-
ter (see Figure 34).
Figure 34. Framing Error Block Diagram
When this feature is enabled, the receiver checks each incoming data frame for a valid
stop bit. An invalid stop bit may result from noise on the serial lines or from simultaneous
transmission by two CPUs. If a valid stop bit is not found, the Framing Error bit (FE) in
SCON register (See Table 56) bit is set.
Software may examine FE bit after each reception to check for data errors. Once set,
only software or a reset can clear FE bit. Subsequently received frames with valid stop
bits cannot clear FE bit. When FE feature is enabled, RI rises on stop bit instead of the
last data bit (See Figure 35 and Figure 36).
Figure 35. UART Timings in Mode 1
Framing error detection
Automatic address recognition
SMOD0 = X
SMOD0 = 1
RXD
SM0/FE
FE
RI
SMOD1
SMOD0
SM1
Start
Bit
D0
SM2
-
D1
REN
Set FE Bit if Stop Bit is 0 (framing error) (SMOD0 = 1)
SM0 to UART Mode Control (SMOD0 = 0)
POF
To UART Framing Error Control
D2
TB8
GF1
D3
Data Byte
RB8
GF0
D4
D5
PD
TI
D6
IDL
RI
D7
SCON (98h)
PCON (87h)
Stop
Bit
4338F–USB–08/07