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NXP Semiconductors
AH1721
SJA1105SMBEVM UM
AH1721
All information provided in this document is subject to legal disclaimers.
© NXP Semiconductors N.V. 2018. All rights reserved.
User Manual
Rev. 1.00
— 16 July 2018
10 of 35
LED label Color
Description:
P2-L,
P2-R,
P3-L,
P3-R
L=green
R=yellow
LEDs integrated in the GBit connectors P2 and P3
L is controlled by the GBit PHY’s LED2 output, and R by the LED1
output. In Tri-Color dual-LED mode the following settings are used:
state
L = green
R = yellow
Link off
off
off
1000 Link, no activity
on
off
1000 Link/Activity (RX, TX)
blink
off
100 Link, no activity
off
on
100 Link/Activity (RX, TX)
off
blink
10 Link, no activity
on
on
10 Link/Activity (RX, TX)
blink
blink
D6, D7,
D8
green
Power-Good LEDs for the voltages generated by switching regulators.
D6 = 5V0
D7 = 3V3
D8 = 2V5
D11, D12
green
Power-Good LEDs for the voltages generated by LDOs.
D11 = 1V8
D12 = 1V2
D3
green
Labeled “ALIVE”. General purpose LED connected to the uC. Used by
the
μC software as a heartbeat. This LED should continuously blink if
the example SW is running.
D17
green
General purpose LED connected to the uC. No special meaning.
D13
green
PTP LED. The LED is connected to SwitchA’s PTP_CLK output by a
transistor inverter. If PTP_CLK is low, the LED is off.
Positions of the LEDs are shown in Fig 4.
4.8 Jumper blocks and connectors
The position of the jumper blocks and connectors is shown in Fig 4.
Table 4.
Jumper blocks and connectors
Name
Meaning/Usage
J1
Power Jack 12V input
J2
USB Type B receptacle for the serial link to PC
J3,J5
CAN bus termination setting; J3 = CAN_L, J5 = CAN_H
1-2: 120R termination active (used for an end node on the CAN bus)
2-3: 2k6 termination active (used for a middle node on the CAN bus)
No jumper: No termination
J4
Fast Ethernet RJ45 receptacle with LEDs
J6
Jumper block for selecting the source of the enable signal VREG_EN to the
switching power regulators (5V0, 3V3, 2V5)
2-3: 12V0
– regulators permanently enabled
1-2: VREG_EN is under control of the PHYs and the processor
– see ch 6.3 for
sleep/wakeup