Datasheet

© 2007 Microchip Technology Inc. DS21801E-page 55
MCP2515
9.0 RESET
The MCP2515 differentiates between two resets:
1. Hardware Reset – Low on RESET
pin.
2. SPI Reset – Reset via SPI command.
Both of these resets are functionally equivalent. It is
important to provide one of these two resets after
power-up to ensure that the logic and registers are in
their default state. A hardware reset can be achieved
automatically by placing an RC on the RESET
pin. (see
Figure 9-1). The values must be such that the device is
held in reset for a minimum of 2 µs after V
DD reaches
operating voltage, as indicated in the electrical
specification (t
RL).
FIGURE 9-1: RESET PIN CONFIGURATION EXAMPLE
RESET
R1
(2)
VDD
VDD
R
C
D
(1)
Note 1: The diode D helps discharge the capacitor quickly when VDD powers down.
2: R1 = 1 kΩ to 10 kΩ will limit any current flowing into RESET
from external
capacitor C, in the event of RESET pin breakdown due to Electrostatic
Discharge (ESD) or Electrical Overstress (EOS).