LTP5900 Mote Datasheet

Dust Networks

13

SP_CTS

¯¯¯¯¯¯¯.

MT_CTS

¯¯¯¯¯¯¯

Output

MT_CTS

¯¯¯¯¯¯¯ provides packet-level flow control for packets transferred from the microprocessor

to the mote that are destined for transfer over the network. Upon reset, following boot the

mote will negate MT_CTS

¯¯¯¯¯¯¯ until the mote establishes a wireless network connection. During

operation, the mote will negate MT_CTS

¯¯¯¯¯¯¯ if the mote does not have sufficient buffering to

accept another packet. MT_CTS

¯¯¯¯¯¯¯ will also remain high if the mote is not part of the network.

The microprocessor must check that the MT_CTS

¯¯¯¯¯¯¯ pin is low before initiating each serial

packet for wireless transmission.

Note that the mote may receive local serial packets at any time regardless of the MT_CTS

¯¯¯¯¯¯¯

state. For a list of local commands, see the SmartMesh IA-510 Mote Serial API Guide.

TIME

¯¯¯¯

Input

The TIME

¯¯¯¯ pin can be used for triggering a timestamp packet. Its usage is optional.

8.3.3

UART AC Timing

Table 15

UART Timing Values

Variable

Description

Min

Max

Units

tRX_BAUD

Deviation from baud rate

-2

+2

%

tRX_STOP

Number of stop bits (9600 bps)

1

bit period

tRX_STOP

Number of stop bits (115.2 kbps)

1.5

bit period

tTX_BAUD

Deviation from baud rate

-1

+1

%

tTX_STOP

Number of stop bits

1

bit period

tSP_CTS to

MT_RTS

Assertion of SP_CTS

¯¯¯¯¯¯¯ to negation of MT_RTS

¯¯¯¯¯¯¯

0

10

ms

tMT_RTS to

SP_CTS

Assertion of MT_RTS

¯¯¯¯¯¯¯ to assertion of SP_CTS

¯¯¯¯¯¯¯

500

ms

tMT_RTS retry

Time from a MT_RTS

¯¯¯¯¯¯¯ timeout to the retry.

500

ms

tSP_CTS to TX

Assertion of SP_CTS

¯¯¯¯¯¯¯ to start of byte

0

10

ms

tTX to SP_CTS

Start of byte to negation of SP_CTS

¯¯¯¯¯¯¯

1

bit period

tSP_CTS ack PW

Negation pulse width of SP_CTS

¯¯¯¯¯¯¯

500

ns

tdiag_ack_timeout*

The mote responds to all requests within this time.

125

ms

tinterbyte_timeout

Falling edge of TX to falling edge of SP_CTS

¯¯¯¯¯¯¯ (Mode 3 only)

7.1

ms

tinterpacket_delay

The sender of an HDLC packet must wait at least this amount

of time before sending another packet

20

ms

* For more information about supported requests and details on when tdiag_ack_timeout applies, refer to the

SmartMesh IA-510 Mote Serial API Guide

.