Sundance Spas ST201 - Manual (Page 52)

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Sundance Technology ST201 PRELIMINARY draft 2
The loopback modes available to a host system when using the ST201 are shown in Table 3.
External loopback type is controlled by the Mll PHY device. The host system must enable a loopback mode
within MII PHY device using the MII Management Interface. For the true “on-the-wire” loopback mode, use
a loopback plug (connector), clear all of the loopback bits, set the FullDuplexEnable bit in the MACCtrl reg-
ister, and enable the full duplex mode within the MII PHY device.
30 Paused This read-only status bit is set by ST201 to indicate that a PAUSE MAC
Control frame had been received and halted the transmit MAC for the
duration of the pause_time. It is cleared when the MAC can resume
transmission.
31 Reserved Reserved for future use. Should be set to 0.
Loopback Mode FIFOLoopback MACLoopback FullDuplexEnable
FIFO Loopback 1 0 x
MAC Loopback 0 1 x
External Loopback (MII) or
True “On-wire” External 0 0 1
TABLE 3: ST201 Loopback Modes
BIT BIT NAME BIT DESCRIPTION