NRF9E5 NORDIC SEMICONDUCTOR, NRF9E5 Datasheet - Page 86

• Manufacturer Part Number: NRF9E5
• Description: TRX, 430-928MHZ, MCU/ADC/PWM, SMD
• Manufacturer: NORDIC SEMICONDUCTOR

Specifications of NRF9E5

• Receiving Current: 12.5mA
• Transmitting Current: 30mA
• Data Rate: 50Kbps
• Frequency Range: 430MHz To 928MHz
• Modulation Type: GFSK
• Rf Ic Case Style: QFN
• No. Of Pins: 32
• Supply Voltage Range: 1.9V To
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

PRODUCT SPECIFICATION
nRF9E5 Single Chip Transceiver with Embedded Microcontroller and ADC
18.9.2 Mode 1
Mode 1 provides standard asynchronous, full-duplex communication, using a total of ten
bits: one start bit, eight data bits, and one stop bit. For receive operations, the stop bit is
stored in RB8. Data bits are received and transmitted LSB first.
18.9.2.1 Mode 1 Baud Rate
The mode 1 baud rate is a function of timer overflow. Serial port can use either Timer 1
or Timer 2 to generate baud rates. Each time the timer increments from its maximum
count (0xFF for Timer 1 or 0xFFFF for Timer 2), a clock is sent to the baud-rate circuit.
The clock is then divided by 16 to generate the baud rate. When using Timer 1, the
SMOD bit selects whether or not to divide the Timer 1 rollover rate by 2. Therefore,
when using Timer 1, the baud rate is determined by the equation:
SMOD is SFR bit PCON.7
When using Timer 2, the baud rate is determined by the equation:
To use Timer 1 as the baud-rate generator, it is best to use Timer 1 mode 2 (8-bit counter
with auto-reload), although any counter mode can be used. The Timer 1 reload value is
stored in the TH1 register, which makes the complete formula for Timer 1:
The 4 in the denominator in the above equation can be obtained by setting the T1M bit
in the CKCON SFR. To derive the required TH1 value from a known baud rate (when
TM1 = 0), use the equation:
You can also achieve very low serial port baud rates from Timer 1 by enabling the
Timer 1 interrupt, configuring Timer 1 to mode 1, and using the Timer 1 interrupt to
initiate a 16-bit software reload. Table Table 72 lists sample reload values for a variety
of common serial port baud rates.
Main office: Nordic Semiconductor ASA - Vestre Rosten 81, N-7075 Tiller, Norway -Phone [phone] - Fax [phone]
Revision: 1.3
Baud Rate =
Baud Rate =
Baud Rate =
TH1 = 256 -
2
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2
SMOD
32
SMOD
32
Timer
128
x Timer 1 Overflow
x
2
SMOD
2
4
Baud
16
Overflow
x
(256
clk
clk
Rate
-
TH1)
June 2006