NXP Semiconductors freescale semiconductor MC13211, Reference Manual

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MC1321x Reference Manual, Rev. 1.6
Freescale Semiconductor 5-1
Chapter 5
Modem SPI Register Descriptions
5.1 Overview
All control, reading of status, writing of data, and reading of data is done through the MC1321x SPI port.
The host microcontroller accesses the transceiver through SPI “transactions” in which multiple bursts of
byte-long data are transmitted on the SPI bus. Each transaction is three or more bursts long depending on
the transaction type, and these are described in detail in
Section 4.9, “Modem SPI Singular Transactions” .
Transactions are always read accesses or write accesses to register addresses. The associated data for any
single register access is always 16 bits in length. This chapter describes all the registers that users should
access in the MC1321x. Undocumented addresses should not be accessed.
NOTE
• Register default values for reserved fields should not be modified unless
specifically noted. Freescale recommends that all writes to control
register fields that only modify part of the 16-bit word be done as a
read-modify-write operation.
• The newest version of the MC1321x now uses an updated transceiver
device. Although fully compliant with earlier versions of the
transceiver, proper performance of the radio requires that the following
modem registers be over-programmed:
Register 0x31 to 0xA0C0
Register 0x34 to 0xFEC6
These registers must be over-programmed for MC1321x devices in which the modem
Chip_ID Register 0x2C reads 0x6800.