mrf89xa Microchip Technology Inc., mrf89xa Datasheet - Page 77

• Manufacturer Part Number: mrf89xa
• Description: Ultra-low Power, Integrated Ism Band Sub-ghz Transceiver
• Manufacturer: Microchip Technology Inc.

3.8
3.8.1
The MRF89XA data processing blocks are as
illustrated in the Figure 3-16. Its role is to interface the
data to/from the modulator/demodulator and the host
microcontroller access points (SPI, Interrupts (IRQ0
and IRQ1), DATA pins). It also controls all the configu-
ration registers.
The circuit contains several control blocks which are
described in the following paragraphs.
The MRF89XA implements several data operation
modes, each with their own data path through the data
processing section. Depending on the data operation
mode selected, some control blocks are active while
others remain disabled.
FIGURE 3-16:
TABLE 3-4:
© 2010 Microchip Technology Inc.
Continuous
Buffered
Packet
Data Operation Mode
Data
Data Processing
DATA PROCESSING BLOCK
DIAGRAM
TX/RX
RX
TX
DATA OPERATION MODE SELECTION
Recognition
MRF89XA DATA PROCESSING BLOCK DIAGRAM
SYNC
Handler
Packet
DMODE1
0
0
1
MRF89XA
Preliminary
Control
(+SR)
FIFO
3.8.2
The MRF89XA has three different data operation
modes which can be selected by the user or
programmer:
• Continuous mode: Each bit transmitted or
• Buffered mode: Each byte transmitted or received
• Packet mode (recommended): User only pro-
received is accessed in real time at the DATA pin.
This mode may be used if adequate external sig-
nal processing is available.
is stored in a FIFO and accessed through the SPI
bus. The host microcontroller processing over-
head reduced significantly compared to Continu-
ous mode operation. The packet length is
unlimited.
vides/retrieves payload bytes to/from the FIFO.
The packet is automatically built with preamble,
Sync word, and optional CRC, DC free encoding
and the reverse operation is performed in recep-
tion. The host microcontroller processing over-
head is further reduced compared to Buffered
mode. The maximum payload length is limited to
the maximum FIFO limit of 64 bytes.
DMODE0
0
1
x
DATA OPERATION MODES
CONFIG
DATA
SPI
MRF89XA
FTXRXIREG
FTXRXIREG
FTXRXIREG
Register
DS70622B-page 77
SDO
CSDAT
SCK
SDI
DATA
IRQ1
IRQ0