Cypress CY4672 manual Ping Mode Bridge Only, Idle Mode, Bind Mode Reconnect, KISSBind Mode, Data

WirelessUSB™ Protocol 2.2

Figure 2-3. Protocol Slave

POR

UnBound,

KISSBind disabled

Bound

Idle

Mode

Wait for
user Bind
event	Bind fails

Bind

Mode

Reconnect

Mode

Search for bridge

and sleep if

necessary

UnBound,

KISSBind enabled

KISSBind

Mode

Bridge

found

	Data
Lost	Mode
	Sleep when no data
connection	to be sent
with bridge

2.2.1Ping Mode (Bridge Only)

Ping mode is used by the bridge to find an available channel; channels are unavailable if they are being used by another network with the same PN code, or if there is excessive noise on the channel. The bridge first listens for activity on the selected channel. If the channel is inactive the bridge alter- nately transmits ping packets and listens for ping response packets for a defined* period of time. During ping mode the bridge also checks the Receive Signal Strength Indicator (RSSI) of the radio in order to determine if a non-WirelessUSB device is using this channel (or a WirelessUSB device on the same channel using a different PN code). If a ping response is received, indicating that another bridge is using this channel the bridge selects the next channel using the channel selection algorithm and repeats this procedure. The bridge also selects another channel using the channel selection algorithm if RSSI is high; this indicates that there are other RF sources on the channel. If a ping response is not received and RSSI is low, the bridge assumes the channel is available and moves to data mode. Bridges send ping response packets in response to all received ping packets if the bridge is in data mode. HIDs never respond to ping packets.

[*The timeout value is configurable using the PING_NUM_RSSI define.]

16 CY4672 Reference Design Guide, Document # 001-16968 Revision **

[+] Feedback