8.2.2 Reset Timing
Vcc
X1 clock
T2.2.1
T2.2.4
Hardware
RESET_N
32 clocks
MDC
T2.2.2
Latch-In of Hardware
Configuration Pins
T2.2.3
input
output
Dual Function Pins
Become Enabled As Outputs
Parameter
Description
Notes
Min
Typ Max Units
T2.2.1
Post RESET Stabilization time MDIO is pulled high for 32-bit serial man-
prior to MDC preamble for reg- agement initialization
ister accesses
3
µs
T2.2.2
Hardware Configuration Latch- Hardware Configuration Pins are de-
in Time from the Deassertion scribed in the Pin Description section
of RESET (either soft or hard)
3
µs
T2.2.3
T2.2.4
Hardware Configuration pins
transition to output drivers
50
ns
RESET pulse width
X1 Clock must be stable for at min. of 1us
during RESET pulse low time.
1
µs
Note: It is important to choose pull-up and/or pull-down resistors for each of the hardware configuration pins that provide
fast RC time constants in order to latch-in the proper value prior to the pin transitioning to an output driver.
65
www.national.com
TI [ TEXAS INSTRUMENTS ]
