User Manual
BCM1250/BCM1125/BCM1125H
10/21/02
B r o a d c o m C o r p o r a t i o n
Document
1250_1125-UM100CB-R
Section 9: Ethernet MACs Page
287
shows the flow for the main loop for sending and reading bits.
Figure 59: MDIO Flows
Single Write to mac_mdio
mdc = 0
mdio_out = bit to send
mdio_dir = 0
Wait Half Clock
Cycle Time
Single Write to mac_mdio
mdc = 1
mdio_out = bit to send
mdio_dir = 0
Wait Half Clock
Cycle Time
More
to
Send?
Single Write to mac_mdio
mdc = 0
mdio_dir = 1
Write Bits
No
Yes
Single Write to mac_mdio
mdc = 1
mdio_dir = 1
Wait Half Clock
Cycle Time
Single Write to mac_mdio
mdc = 0
mdio_dir = 1
Wait Half Clock
Cycle Time
Read Bit
From mdio_in
Read Bits
More
To
Read?
No
Yes