Datasheet

PRODUCTPREVIEW
MDIO_CLK Output)
1
2
MDIO_DATA (Input)
AM3359, AM3358, AM3357
AM3356, AM3354, AM3352
SPRS717E –OCTOBER 2011–REVISED JANUARY 2013 www.ti.com
5.4 Ethernet Media Access Controller (EMAC) and Switch
5.4.1 Ethernet MAC and Switch Electrical Data and Timing
The Ethernet MAC and Switch implemented in the AM335x device supports GMII mode, but the AM335x
design does not pin out 9 of the 24 GMII signals. This was done to reduce the total number of package
terminals. Therefore, the AM335x device does not support GMII mode. MII mode is supported with the
remaining GMII signals.
The AM335x ARM Cortex-A8 Microprocessors (MPUs) Technical Reference Manual (literature number
SPRUH73) and this document may reference internal signal names when discussing peripheral input and
output signals since many of the AM335x package terminals can be multiplexed to one of several
peripheral signals. For example, the AM335x terminal names for port 1 of the Ethernet MAC and switch
have been changed from GMII to MII to indicate their Mode 0 function, but the internal signal is named
GMII. However, documents that describe the Ethernet switch reference these signals by their internal
signal name. For a cross-reference of internal signal names to terminal names, see Table 2-7.
Operation of the Ethernet MAC and switch is not supported for OPP50.
Table 5-3. Ethernet MAC and Switch Timing Conditions
TIMING CONDITION PARAMETER MIN TYP MAX UNIT
Input Conditions
t
R
Input signal rise time 1
(1)
5
(1)
ns
t
F
Input signal fall time 1
(1)
5
(1)
ns
Output Condition
C
LOAD
Output load capacitance 3 30 pF
(1) Except when specified otherwise.
5.4.1.1 Ethernet MAC/Switch MDIO Electrical Data and Timing
Table 5-4. Timing Requirements for MDIO_DATA
(see Figure 5-2)
NO. MIN TYP MAX UNIT
1 t
su(MDIO-MDC)
Setup time, MDIO valid before MDC high 90 ns
2 t
h(MDIO-MDC)
Hold time, MDIO valid from MDC high 0 ns
Figure 5-2. MDIO_DATA Timing - Input Mode
Table 5-5. Switching Characteristics for MDIO_CLK
(see Figure 5-3)
NO. PARAMETER MIN TYP MAX UNIT
1 t
c(MDC)
Cycle time, MDC 400 ns
2 t
w(MDCH)
Pulse duration, MDC high 160 ns
3 t
w(MDCL)
Pulse duration, MDC low 160 ns
4 t
t(MDC)
Transition time, MDC 5 ns
114 Peripheral Information and Timings Copyright © 2011–2013, Texas Instruments Incorporated
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