MK50H25N ST Microelectronics, Inc., MK50H25N Datasheet - Page 28

• Manufacturer Part Number: MK50H25N
• Description: High Speed Link Level Controller
• Manufacturer: ST Microelectronics, Inc.

MK50H25
4.2.2 Station Addresses
The MK50H25 uses the values in Local and Remote Station Address fields of the Initialization Block for
filtering received frames and for the address field of transmitted frames. The MK50H25 transmits com-
mands with the Remote Station Address in the frame address field, and it transmits responses with the
Local Station Address in the frame address field. The MK50H25 compares the received frame address to
the Local and Remote Station Address fields. If the received frame address matches the Local Station
Address field the MK50H25 will treat the received frame as a command. If the received frame address
matches the Remote Station Address field the MK50H25 will treat the received frame as a response. The
MK50H25 also supports the reception of frames with a global address of all 1’s, if the XIDE bit
(CSR2<08>) is set =1. In this case, it will treat a frame received with a global address as a comand,
whether or not it is an XID/TEST frame. The MK50H25 however, will transmit a frame with a global ad-
dress if all 1’s have been placed in the appropriate Local/Remote Address fields prior to an Init primitive
(UPRIM=2, CSR1) being issued.
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04
03
02:00
DTFCS
FCSS
LBACK
depending on FCSS, but no
whether the FCS is correct. If the received frame has no FCS, then the
FCSEN bit (in IADR+16) should be set so that MCNT will reflect the
correct length of the received frame.
Disable Transmitter FCS. When DTFCS=0, the transmitter will generate
and append the FCS to each signal unit. When DTFCS = 1, the FCS
logic is disabled, and no FCS is generated with transmitted frames.
Setting DTFCS = 1 is useful in loopback testing for checking the ability
of the receiver to detect an incorrect FCS.
FCS Select. When FCSS = 1, a 16-bit FCS is selected otherwise a 32-
bit FCS is used.
Loopback Control puts MK50H25 into one of several loopback
configurations. (Note: If RTSEN (CSR5<04>) = 1, then RTS (pin 26)
must be connected to CTS (pin 30) for proper loopback operation.)
LBACK
0
4
5
6
7
Normal operation. No loopback.
Simple loopback. Receive data and clock are driven internally
by transmit data and clock. Transmit clock must be supplied
externally
Clockless loopback. Receive data is driven internally by
transmit data. Transmit and receive clocks are driven by
SYSCLK divided by 8.
Silent loopback. Same as simple loopback with td pin forced to
all ones.
Silent clockless loopback. Combination of Silent and Clockless
loopbacks. Receive data is driven internally by transmit data,
transmit and receive clocks are driven by SYSCLK divided by
8. The TD pin is forced to all ones.
check is performed
DESCRIPTION
to
determine