Data Sheet
JODY-W1 series - Data Sheet
UBX-16013635 - R13 Contents Page 23 of 50
Confidential
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-- D$$- -- D$$-
, , , , , , , ,
Clock Period T Ttr - - - Ttr - - T a
Master Mode: Clock generated by transmitter or receiver
HIGH tHC 0.35Ttr
- - - 0.35Ttr
- - - b
Low tLC 0.35Ttr
- - - 0.35Ttr
- - - b
Slave Mode: Clock accepted by transmitter or receiver
HIGH tHC - 0.35Ttr
- - - 0.35Ttr
- - c
Low tLC - 0.35Ttr
- - - 0.35Ttr
- - c
Rise time tRC - - 0.15Ttr
- - - - - d
Transceiver
Delay tdtr - - - 0.8Ttr - - - - e
Hold time thtr 0 - - - - - - - d
Receiver
Setup time tsr - - - - - 0.2Tr - - f
Hold time thr - - - - - 0 - - f
"/9")!
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a. The system clock period T must be greater than T
tr
and T
r
because both the transmitter and
receiver have to be able to handle the data transfer rate.
b. At all data rates in master mode, the transmitter or receiver generates a clock signal with a fixed
mark/space ratio. For this reason, t
HC
and t
LC
are specified with respect to T.
c. In slave mode, the transmitter and receiver need a clock signal with minimum HIGH and LOW
periods so that they can detect the signal. So long as the minimum periods are greater than
0.35T
r
, any clock that meets the requirements can be used.
d. Because the delay (t
dtr
) and the maximum transmitter speed (defined by T
tr
) are related, a fast
transmitter driven by a slow clock edge can result in t
dtr
not exceeding t
RC
which means t
htr
becomes zero or negative. Therefore, the transmitter has to guarantee that t
htr
is greater than or
equal to zero, so long as the clock rise-time t
RC
is not more than t
RCmax
, where t
RCmax
is not less
than 0.15T
tr
.
e. To allow data to be clocked out on a falling edge, the delay is specified with respect to the rising
edge of the clock signal and T, always giving the receiver sufficient setup time.
f. The data setup and hold time must not be less than the specified receiver setup and hold time.
-"+(!
2.7
An external handshake interface is available
4
to enable signaling between the JODY-W1 series
modules and an external co-located wireless device to manage wireless medium sharing for optimal
performance.
4
Firmware support is pending. Contact u-blox support for further information.