Navman LA000508 - Manual (Page 11)

11 LA000507G © 2006 Navman New Zealand. All rights reserved. Proprietary information and specifications subject to change without notice.
4.2 Data input output specifications
All communications between the Jupiter 20 receiver and external devices are through the I/O
surface mount pads. These provide the contacts for power, ground, serial I/O and control. Power
requirements are discussed in Section 4.1.
4.2.1 Voltage levels
The I/O connector voltage levels measured at PWR_IN = 3 V are shown in Table 4‑3.
Signal Parameter Value
TXD & RXD
GPIOs
SPI bus
V
IH
(min) 2.0 V
V
IH
(max) PWR_IN +0.1 V
V
IL
(min) 0.1 V
V
IL
(max) 0.8 V
V
OH
(min) at I
OH
2 mA 2.0 V
V
OH
(max) PWR_IN
V
OL
(min) 0
V
OL
(max) at I
OL
–2 mA 1.0 V
Reset input*
max capacitance Cmax 100 pF
input current max –600 μA
pulse time min 200 μs
*Reset input should not be driven high by external circuits. It
is recommended that this input is driven low by an open drain
interface.
Table 4-3: Interface voltage levels
4.2.2 I/O surface mount pads
Details of the surface mount pad functions are shown in Table 4‑4 and 4‑5.
Pad
No.
Name Type Description
8* GYRO_IN I gyro input (analogue 0–5 V)
27* FWD/REV I fwd/rev input (low=forward, high=reverse)
28* WHEEL_TICKS I wheel tick input
* See also Table ‑ for J20/J20S pad functions
Table 4-4: J20D receiver pad functions