User`s guide

Aironet Wireless Communications, Inc. 8-4 Confidential and Proprietary
Migrating from the LM2000 to the PC4500/4800
The PC4500/4800 supports the same PLAP frame format as the LM2000. The SYNC_REQ,
SYNC_ACK, DATA and DOWNLOAD frames are identical between the two products. In order to take
full advantage of the PC4500/4800, the user must support the new HOST_COMMAND and
COMMAND_RESPONSE frame types.
A minimal requirement for migration is the implementation of the use of two stop bits. The
PC4500/4800 serial interface does not default to any given baud rate and therefore must ‘learn’ which
rate is being used by the host.
PLAP Commands
Table 8-1 lists the valid PLAP commands.
Table 8-1. PLAP Commands
FRAME
TYPE
(hex)
NAME DIRECTION DESCRIPTION
00 / 80 SYNC_REQ Host to PC4500/4800 Verify connectivity
01 / 81 SYNC_ACK PC4500/4800 to Host Response to SYNC_REQ frame
02 / 82 DATA Both Data frames
04 / 84 CONFIGURE Host to PC4500/4800 Used to perform quick configuration
07 / 87 DOWNLOAD Host to PC4500/4800 Used to upgrade firmware
10 / 90 HOST_COMMAND Host to PC4500/4800 Issue host commands
11 / 91 COMMAND_RESPONSE PC4500/4800 to Host Response to host command
SYNC_REQ
Frame Type: 0x00, 0x80
struct sync_req_frm {
unsigned char Frame_type; // 0x00, 0x80
unsigned short Length; // 0x0006
unsigned short Checksum; // 0x0006, 0x0086
unsigned char EOT; // 0x04
};
The sync frames are used to verify connectivity of the peripheral interface. Each PLAP
implementation will assume that its receiver is synchronized and attempt to verify that its
transmitter is synchronized with the remote receiver. The PLAP process on the PC4500/4800 will
immediately transmit a SYNC-ACK frame in response to a SYNC-REQ frame.
Compatibility: PC4500/4800 and LM2000