CC2520_11 Datasheet, PDF (56/133 Pages) Texas Instruments – 2.4 GHZ IEEE 802.15.4/ZIGBEE RF TRANSCEIVER

CC2520 DATASHEET
2.4 GHZ IEEE 802.15.4/ZIGBEE® RF TRANSCEIVER
SWRS068 – DECEMBER 2007
Mnemonic
DPU_DONE_H
MEMADDR_ERROR
USAGE_ERROR
OPERAND_ERROR
Num
(hex)
0x0F
0x10
0x11
0x12
SPI_ERROR
RF_NO_LOCK
0x13
0x14
RX_FRM_ABORTED
0x15
RXBUFMOV_TIMEOUT 0x16
UNUSED
0x17
Description
High priority DPU operation completed. Will not be issued if operation fails
or is aborted.
An illegal address has been used for an instruction. Instruction is aborted.
Instruction performed in a context that does not permit this instruction.
Instruction is aborted.
Wrong format for instruction. Instruction is aborted. This will happen for a
multi-byte fixed-length instruction if CSn is raised on a byte boundary but
before the required number of operands has been transferred.
An SPI transfer was aborted by raising CSn in the middle of a byte. (I.e.
not on a byte boundary)
If no lock has been found before 256 us after entering RX this exception
will go active. Also a negative edge on LOCK_STATUS when in RX will
trigger this exception.
Frame reception aborted. Not issued when RX_OVERFLOW occurs.
RXBUFMOV has timed out. There were not enough bytes available in the
RX FIFO and the wait time set by DPUCON.RXTIMEOUT has expired.
Reserved
14.1 Exceptions on GPIO Pins
All exception flags can be routed individually to a GPIO pin by writing the CTRLn value corresponding to the
desired exception in Table 8 into the GPIOCTRLn registers.
CC2520 has two exception channels, A and B, that let the user select a collection of exceptions to combine
to output on a GPIO pin. If any of the selected exceptions goes active, the GPIO pin goes active. It is also
possible to output the complementary collection of exceptions of each of the two channels.
Example: Collect RF_IDLE and RX_UNDERFLOW in exception channel B and output on GPIO3.
• Write 0x22 to GPIOCTRL3. Set GPIO3 as output and select exception channel B from the GPIO
configuration table in section 12.6.
• Write 0x21 to EXCMASKB0. Select RF_IDLE and RX_UNDERFLOW exceptions in accordance with
table Exceptions overview (section 16).
• Write 0x00 to EXCMASKB1. Mask all other exceptions.
• Write 0x00 to EXCMASKB2. Mask all other exceptions.
The complementary exception channel B with the settings in the example above will include all other
exceptions than RF_IDLE and RX_UNDERFLOW. This channel can be routed to another GPIO pin by
writing 0x24 to the corresponding GPIOCTRLn register.
Exceptions linked to GPIO pins separately or as a group in a channel will be consistent with the
corresponding bits in the EXCFLAGn registers. EXCFLAGn register bits that are high can only be cleared by
writing zero to the bit.
14.2 Predefined Exception Channels
There are two predefined exception channels that can be observed on GPIO pins. They are not included in
the status byte and no complementary channel is available.
The first predefined exception channel is a collection of exceptions that indicate that something has gone
wrong during RX.
• RX_UNDERFLOW
• RX_OVERFLOW
• RX_FRM_ABORTED
• RXBUFMOV_TIMEOUT
56
WWW.TI.COM