Texas Instruments TLK6002, User Manual, Page: 20 / 73

MAIN RST
R
S
T
R
S
T
MAIN
MANUAL RESET
GND
MAIN
RST BUTTON
RST
GND
JMP15
S
W
1
D
1
D
2
JMP14
Reset
www.ti.com
10 Reset
The TLK6002EVM comes configured for Manual Reset operations involving the Pushbutton Reset Switch
(SW1). When switch SW1 is pressed, the TLK6002 device RESET pin (RST_N) goes LOW and the entire
TLK6002 device is reinitialized. A TI TPS3125J18 Ultra Low Voltage Processor Supervisory Circuit is used
to control the Reset line. During power on, RESET pin of U2 is asserted when the supply voltage
becomes higher than 0.75 V. Thereafter, the supply voltage supervisor monitors the voltage and keeps
RESET output active as long as the voltage remains below the threshold voltage (V
IT
). An internal timer
delays the return of the output to the inactive state (high) to ensure proper system reset. The delay time, t
d
= 180 ms, starts after the voltage has risen above the threshold voltage (V
IT
).
A manual reset input to the supervisory circuit, MR, accepts the input from the pushbutton switch SW1. A
low level at MR causes RESET to become active, thus resetting the TLK6002 device whenever the
pushbutton RESET is pressed. By placing a jumper on JMP15, the Manual Reset (MR) is tied hard to
ground causing the TLK6002 to be held in a constant state of Reset without the need to continually hold
the Reset Pushbutton SW1. The Supervisory circuit released the Reset line to a HIGH 180 ms (t
d
) from
the time the MR line becomes greater than the threshold voltage (V
IT
).
By removing the jumper from JMP14, the Supervised Reset Circuit is disconnected from the RST_N line.
Reset control from an external controller or piece of equipment can be connected directly to pin 2
(RST_N) of JMP14 and a ground pin GND has been added to the JMP14 header next to the RST_N pin
to allow easy access for the return current on that cable.
Figure 12. RESET Switch – SW1, JMP14, or JMP15
NOTE: The Jumper on JMP14 connecting RESET SW to RST_N must be connected as shown in
order to cause the TLK6002 to be reset and reinitialized If switch SW1 is pressed, the device
RESET pin (RST_N) goes LOW, the entire TLK6002 device is reinitialized.
20 TLK6002 Dual-Channel, 0.47-Gbps to 6.25-Gbps, Multi-Rate Transceiver SLLU132 – October 2010
Evaluation Module
Submit Documentation Feedback
Copyright © 2010, Texas Instruments Incorporated