Laird AC4490, Руководство по интеграции оборудования

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AC4490 Hardware Integration Guide
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Figure 4: Even Parity Bit
Note: Enabling parity cuts throughput and the interference buffer in half.
Table 5 displays supported asynchronous serial data formats:
Table 5: Supported Serial Formats
Data Bits Parity Stop Bits Transceiver Programming Requirements
8 N 1 Parity Disabled
7 N 2 Parity Disabled
7 E, O, M, S 1 Parity Disabled
9 N 1 Parity Enabled
8 N 2 Parity Enabled
8 E, O, M, S 1 Parity Enabled
7 E, O, M, S 2 Parity Enabled
Mark (M) corresponds to 1 & Space (S) corresponds to 0
Serial Interface Baud Rate
This two-byte value determines the baud rate used for communicating over the serial interface between the
OEM Host and the transceiver. This rate is independent of the RF baud rate, which is fixed at 76.8 Kbps.
Table 6 lists values for some common baud rates.
Note: Baud rates below 1200 baud are not supported.
For a baud rate to be valid, the calculated baud rate must be within ±3% of the OEM host baud rate. If the
Test pin (pin 12) is pulled Logic Low at reset, the baud rate will be forced to 9600. For baud rate values other
than those shown in
Table 6 , the following equations can be used:
BAUD =
14.7456 × 10
6
64 × 𝐷𝑒𝑠𝑖𝑟𝑒𝑑 𝐵𝑎𝑢𝑑
𝐵𝑎𝑢𝑑𝐻 = 𝐴𝑙𝑤𝑎𝑦𝑠 0
𝐵𝑎𝑢𝑑𝐿 = 𝐿𝑜𝑤 8 𝑏𝑖𝑡𝑠 𝑜𝑓 𝐵𝐴𝑈𝐷 (𝑏𝑎𝑠𝑒 16)
Table 6: Baud Rate / Interface Timeout
Baud Rate BaudL (0x42) BaudH (0x43)
Minimum Interface
Timeout (0x58)
Stop Bit Delay
(0x3F)
115200 0xFE 0x00 0x02 0xFF
57600 1 0xFC 0x00 0x02 0x03
38400 0xFA 0x00 0x02 0x08