LZ85202
4
IrDA Control Host Controller with USB Interface User
’
s Guide
The IrDA Control MAC layer (IrDA Control-MAC) manages the IrDA Control infrared wire-
less link between the Host device and the Peripherals. Actual activity of the MAC layer is
shown below.
The Host device will poll
‘
Bound
’
Peripherals in a certain order. The Host device will
insert the communication data (the information forwarded from Host HID LLC Layer) into
the polling packet for each Peripheral.
The Host device will then wait for the corresponding response packets from the Peripherals.
The received corresponding packets include the communication data from the Peripherals.
The Host device will extract these data packets and forward them to its HID LLC layer.
In the event that the corresponding packets from the Peripheral are missing for a certain
time period, the Host device will stop polling them. This state will be seen when the user
stops moving the Peripherals. This state is expressed as
‘
The Peripheral is in an
Unbound state
’
. On the other hand, while the Peripheral is polled, this state is expressed
as
‘
The Peripheral is in the Bound state
’
. The Host device will immediately re-start poll-
ing the Peripheral when the Host device receives the IrDA Control infrared signal trans-
mitted from the Unbound Peripherals. At this time it will again be bound. This step
requires that the Peripheral was previously enumerated.
The HID LLC layer provides error correction, data re-sending, and flow management ser-
vices between the USB Dongle and peripherals. The HID LLC layer formats information sent
by the Peripherals to the Host device. The USB-IrDA Control bridge layer provides a data
Communication Bridge between the USB data and the Peripheral data. It ensures inter-oper-
ability between the USB data packets and the data packet sent by the IrDA Control periph-
erals. The USB controller enables the USB interface for communication with the PC.
As described, five functions are PHY layer, MAC layer, HID LLC layer, USB-IrDA Control
bridge layer, and USB controller, are required for the USB Dongle implementation.
The HC is embedded with four of the five functions (the MAC layer and HID LLC layer, USB-
IrDA Control bridge layer, and USB controller), enabling a simple single-chip implementation
for the USB Dongle. Supporting devices are the Sharp IrDA Control Infrared transceiver,
USB transceiver and a serial EEPROM. See the IrDA Control Host Controller Interface sec-
tion for details. Figure 4 shows an example of IrDA Control Host device implementation.
Figure 4. IrDA Control Host Dongle Implementation Example
HC
P/N: LZ85202
SERIAL EEPROM
P/N: AT93C56
USB TRANSCEIVER
P/N: PDIUSBP11A
(SEE NOTE 3)
(SEE NOTE 1)
(SEE NOTE 2)
NOTES:
1. See 'Interface with Serial EEPROM' section.
2. See 'Interface with Infrared Transceiver (Front-end, FE)' section.
3. See 'Interface with USB transceiver LSI' section.
INFRARED
TRANSCEIVER
GP2W2001YK
LZ85202-4