LAN8810I-AKZE Datasheet, PDF (90/100 Pages) Microchip Technology – GMII 10/100/1000 Ethernet Transceiver with HP Auto-MDIX Support

GMII 10/100/1000 Ethernet Transceiver with HP Auto-MDIX Support
Datasheet
5.5.4
Reset Timing
Figure 5.4 illustrates the nRESET pin timing requirements. For proper operation, nRESET must be
asserted for no less than t_rstia. In order for valid configuration strap values to be read upon a nRESET
assertion, the t_css and t_csh timing constraints must be followed. In order for CONFIG[3:0] values to be
read at power-up, the t_cs and t_ch timing constraints must be followed. Refer to Section 3.6.1, "Hardware
Reset (nRESET)," on page 27 for additional information.
Note: A hardware reset (nRESET assertion) is required following power-up. Refer to Section 5.5.3,
"Power-On Reset Timing," on page 89 for additional information.
nRESET
Configuration
Straps
Configuration Strap
Pins Output Drive
CONFIG[3:0]
t_rstia
t_css
t_csh
t_otaa
t_odad
t_cs
t_ch
Figure 5.4 Reset Timing
SYMBOL
t_rstia
t_css
t_csh
t_otaa
t_odad
t_cs
t_ch
Table 5.13 Reset Timing Values
DESCRIPTION
MIN
nRESET input assertion time
1
Configuration strap pins setup to nRESET deassertion 200
Configuration strap pins hold after nRESET deassertion 10
Output tri-state after nRESET assertion
Output drive after deassertion
40
CONFIG[3:0] setup to nRESET deassertion
0
CONFIG[3:0] hold after nRESET deassertion
1
TYP
MAX UNITS
μS
nS
nS
50
nS
800
nS
nS
uS
Note: Device configuration straps are latched as a result of nRESET assertion. Refer to Section
3.8.1.1, "Configuration Straps," on page 29 details. Configuration straps must only be pulled
high or low and must not be driven as inputs.
Revision 1.0 (02-06-13)
90
DATASHEET
SMSC LAN8810/LAN8810i