AT94K05AL-25BQU Atmel, AT94K05AL-25BQU Datasheet - Page 131

• Manufacturer Part Number: AT94K05AL-25BQU
• Description: IC FPSLIC 5K GATE 25MHZ 144-LQFP
• Manufacturer: Atmel
• Series: FPSLIC®r

Specifications of AT94K05AL-25BQU

• Core Type: 8-bit AVR
• Speed: 25MHz
• Interface: I²C, UART
• Program Sram Bytes: 4K-16K
• Fpga Sram: 2kb
• Data Sram Bytes: 4K ~ 16K
• Fpga Core Cells: 256
• Fpga Gates: 5K
• Fpga Registers: 436
• Voltage - Supply: 3 V ~ 3.6 V
• Mounting Type: Surface Mount
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 144-LQFP
• For Use With: ATSTK594 - BOARD FPSLIC DAUGHTER FOR STK500
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

4.29.2
1138I–FPSLI–1/08
Data Reception
Figure 4-42
Figure 4-42. UART Receiver
Note:
The receiver front-end logic samples the signal on the RXDn pin at a frequency 16 times the
baud-rate. While the line is idle, one single sample of logic 0 will be interpreted as the falling
edge of a start bit, and the start bit detection sequence is initiated. Let sample 1 denote the first
zero-sample. Following the 1-to-0 transition, the receiver samples the RXDn pin at samples 8, 9
and 10. If two or more of these three samples are found to be logic 1s, the start bit is rejected as
a noise spike and the receiver starts looking for the next 1-to-0 transition.
XTAL
PE1/
PE3
1. n = 0, 1
shows a block diagram of the UART Receiver.
PIN CONTROL
GENERATOR
BAUD RATE
LOGIC
RXDn
(1)
BAUD x 16
DATA RECOVERY
LOGIC
UART CONTROL AND
STATUS REGISTER
DATA BUS
/16
(UCSRnB)
AT94KAL Series FPSLIC
STORE UDRn
BAUD
DATA BUS
RXCn
IRQ
UART CONTROL AND
STATUS REGISTER
SHIFT REGISTER
REGISTER (UDRn)
(UCSRnA)
10(11)-BIT RX
UART I/O DATA
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