nRF24E1 Nordic VLSI, nRF24E1 Datasheet - Page 85

• Manufacturer Part Number: nRF24E1
• Description: 2.4Ghz RF Transceiver With Embedded 8051 Compatible Microcontroller And 9 Input, 10 Bit ADC
• Manufacturer: Nordic VLSI

PRODUCT SPECIFICATION
Figure 10-15 : Serial port Mode 2 Receive Timing
For noise rejection, the serial port establishes the content of each received bit by a
majority decision of three consecutive samples in the middle of each bit time. This is
especially true for the start bit. If the falling edge on rxd_in is not verified by a
majority decision of three consecutive samples (low), then the serial port stops
reception and waits for another falling edge on rxd_in.
At the middle of the stop bit time, the serial port checks for the following conditions:
If the above conditions are met, the serial port then writes the received byte to the
SBUF register, loads the 9th received bit into RB8, and sets the RI bit. If the above
conditions are not met, the received data is lost, the SBUF register and RB8 bit are not
loaded, and the RI bit is not set. After the middle of the stop bit time, the serial port
waits for another high-to-low transition on the rxd_in.
Mode 3 provides asynchronous, full-duplex communication, using a total of eleven
bits:
The mode 3 transmit and receive operations are identical to mode 2. The mode 3 baud
rate generation is identical to mode 1. That is, mode 3 is a combination of mode 2
protocol and mode 1 baud rate. Figure 10-16 illustrates the mode 3 transmit timing.
Mode 3 operation is identical to that of the standard 8051 when Timers 1 and 2 use
CPU_clk/12 (the default).
Nordic VLSI ASA - Vestre Rosten 81, N-7075 Tiller, Norway - Phone [phone] - Fax [phone]
Revision: 1.0
- RI = 0
- If SM2 = 1, the state of the stop bit is 1
- One start bit
- Eight data bits
- One programmable 9th bit
- One stop bit; the data bits are transmitted and received LSB first
(if SM2 = 0, the state of the stop bit does not matter)
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July 2003