DS_S5T8702 Datasheet, PDF (31/62 Pages) Samsung semiconductor – FEEX ALPHANUMERIC DECODER II

FEEX^TM ALPHANUMERIC DECODER II
S5T8702
DECODER-TO-HOST PACKET DESCRIPTIONS
The following sections describe the packets of information that will be sent from the S5T8702 to the host. In all
cases the packets are sent MSB first (bit 7 of byte 3 = bit 31 of the packet = MSB). The S5T8702 decides what
data should be sent to the host. If the S5T8702 is disabled through the checksum feature (see "Checksum
Packet" on page 16 for a description of the checksum feature) the Part ID Packet will be sent. Data Packets
relating to data received over the air are buffered in the 32 packet transmit buffer. The Data packets include
Block Information Word Packets, Address Packets, Vector Packets, and Message Packets.
If the S5T8702 is enabled and a receiver shutdown packet is pending, the receiver shutdown packet will be sent.
If there is no receiver shutdown packet pending, but there is a roaming status packet pending, the roaming status
packet will be sent. If neither the receiver shutdown packet nor the roaming status packet is pending and there is
data in the transmit buffer, a packet from the transmit buffer will be sent. Otherwise, the S5T8702 will send the
Status Packet (which is not buffered). In the event of a buffer overflow, the S5T8702 will automatically stop
decoding and clear the buffer.
It is recommended that the Host be designed to empty the FIFO buffer every block with enough time left over to
read a status packet. This would ensure that any applicable Status Packet would be received within 1 block of the
new status being available.
32
Part ID register
32
Receiver shutdown register
32
Roaming status register
32x32 data packet
32
FIFO transmit buffer
32
Status register
M ₃₂
U
X
SPI transmit register
MISO
Figure 10: FLEX decoder IC SPI Transmit Functional Block Diagram
31