si4430 Silicon Laboratories, si4430 Datasheet - Page 42

• Manufacturer Part Number: si4430
• Description: Si4430 Ism Transceiver
• Manufacturer: Silicon Laboratories

Si4430
6.3. Packet Handler TX Mode
If the TX packet length is set the packet handler will send the number of bytes in the packet length field before
returning to ready mode and asserting the packet sent interrupt. To resume sending data from the FIFO the
microcontroller needs to command the chip to re-enter TX mode Figure 18 provides an example transaction where
the packet length is set to three bytes.
6.4. Packet Handler RX Mode
6.4.1. Packet Handler Disabled
When the packet handler is disabled certain portions of the packet handler are still required. Proper modem
operation requires preamble and sync, as shown in Figure 19. Bits after sync will be treated as raw data with no
qualification. This mode allows for the creation of a custom packet handler when the automatic qualification
parameters are not sufficient. Manchester encoding is supported but the use of data whitening, CRC, or header
checks is not.
6.4.2. Packet Handler Enabled
When the packet handler is enabled, all the fields of the packet structure need to be configured. If multiple packets
are desired to be stored in the FIFO, then there are options available for the different fields that will be stored into
the FIFO. Figure 20 demonstrates the options and settings available when multiple packets are enabled. Figure 21
demonstrates the operation of fixed packet length and correct/incorrect packets.
42
Figure 19. Required RX Packet Structure with Packet Handler Disabled
Preamble
Register
Register
Data
Data
Transmission:
data 1
data 1
data 2
data 2
data 3
data 3
data 4
data 4
data 5
data 5
data 6
data 6
data 7
data 7
data 8
data 8
data 9
data 9
Figure 20. Multiple Packets in RX Packet Handler
Figure 18. Multiple Packets in TX Packet Handler
H
L
Data
FIFO
ength
eader(s)
this will be send in the second transmission
this will be send in the second transmission
this will be send in the first transmission
this will be send in the first transmission
this will be send in the third transmission
this will be send in the third transmission
SYNC
Preliminary Rev. 0.4
rx_multi_pk_en = 0
Data
RX FIFO Contents:
Data
txhdlen = 0
L
0
fixpklen
rx_multi_pk_en = 1
DATA
Data
1
Data
txhdlen > 0
H
L
0
fixpklen
Data
1
H