User's Guide

– –
– –
90 91
PKTOPT - Packet Options
Volatile Address = 0xD3; Non-Volatile Address = 0x83
This register selects options for transferring packet data.
Each bit in the register sets an option as shown in Figure 101.
The TXPKT option allows the module to transmit data in explicit packets.
• TXPKT = 0 (default); a packet transmission is enabled when the
number of waiting bytes reaches BCTRIG bytes, the time since the
last received byte exceeds DATATO ms, the number of waiting bytes
exceeds the number that can be sent within the remaining slot time, or
a Send Packet command is written to the CMD register.
• TXPKT = 1; all bytes written to the module are held until a SENDP
command is written to the CMD register or the CMD line is lowered
with TXnCMD = 1. The DATATO or BCTRIG conditions are ignored with
this option. The transmitted packet consists of the bytes in the buffer
at the time a packet is triggered, even if more data bytes are received
before the packet can be sent.
Figure 100: HumPRO
TM
Series Transceiver Packet Options Command and Response
HumPRO
TM
Series Packet Options
Read Command Read Response
Header Size Escape Address ACK Address Value
0xFF 0x02 0xFE
0xD3
0x83
0x06
0xD3
0x83
V
Write Command
Header Size Address Value
0xFF 0x02
0xD3
0x83
V
HumPRO
TM
Series Transceiver Packet Option Codes
Bit Name Description
0 TXPKT Packet Transmit
1 TXnCMD Transmit when nCMD Lowered
2 RXPKT Packet Receive
3 RXP_CTS Use CTS for RXPKT Transfer
4 - 7 Reserved Reserved
Figure 101: HumPRO
TM
Series Transceiver Packet Option Codes
Multiple outgoing packets can be buffered. Changing this option clears the
incoming buffer, losing un-transmitted or unacknowledged data.
When TXnCMD is 1, lowering the CMD line has the same effect as writing
the SENDP command to the CMD register, triggering buffered data to be
transmitted. Packet grouping is affected by option TXPKT. The minimum
low time on the CMD line to terminate the packet is given in the Electrical
Specifications.
When RXPKT is 1, incoming packets are held until a GETPH, GETPD, or
GETPHD command is written to the CMD register. Transfer uses a Packet
Receive transfer. The CMDHOLD setting has no effect.
When RXPKT is 0, incoming UART data is delivered without headers. The
data flow is controlled by the CMDHOLD setting.
When RXP_CTS is 1, the CTS line is used for the status line during a
Packet Receive transfer and not for controlling data flow into the module.
When it is 0, CTS is used for flow control and CRESP is used for the status
line.