© 2004 Microchip Technology Inc. DS70055C-page 8-17
Section 8. Reset
Reset
8
8.12 Design Tips
Question 1: How do I use the RCON register?
Answer: The initialization code after a Reset should examine RCON and confirm the source of
the Reset. In certain applications, this information can be used to take appropriate action to cor-
rect the problem that caused the Reset to occur. All Reset status bits in the RCON register should
be cleared after reading them to ensure the RCON value will provide meaningful results after the
next device Reset.
Question 2: How should I use BOR in a battery operated application?
Answer: The BOR feature is not designed to operate as a low battery detect, and should be
disabled in battery operated systems (to save current). The Low Voltage Detect peripheral can
be used to detect when the battery has reached its end of life voltage.
Question 3: The BOR module does not have the programmable trip points that my
application needs. How can I work around this?
Answer: There are some applications where the device’s programmable BOR trip point levels
may still not be at the desired level for the application. Figure 8-9 shows a possible circuit for
external brown-out protection, using the MCP100 system supervisor.
Figure 8-9: External Brown-out Protection Using the MCP100
Question 4: I initialized a W register with a 16-bit address, but the device appears to
reset when I attempt to use the register as an address.
Answer: Because all data addresses are 16 bit values, the uninitialized W register logic only
recognizes that a register has been initialized correctly if it was subjected to a word load. Two
byte moves to a W register, even if successive, will not work, resulting in a device Reset if the W
register is used as an address pointer in an operation.
VSS
RST
MCP100
VDD
dsPIC30F
VDD
MCLR
To Next Page
Loading...
