Motorola MC68824 User Manual page 63

II
Table 3-8. Test Buffer Format
Buffer Format:
MSB
F D
Host Data:
C B
Host Data 0
Host Data 2
Host Data 32
TBC Return Data 0
TBC Return Data 2
TBC Return Data 32
Indication 0
A
Data prepared by the host which resides in the first 34 bytes.
TBC Return Data:
Host Data 1
Host Data 3
Host Data 33
TBC Return Data 1
TBC Return Data 3
TBC Return Data 33
Indication 1
LSB
o
Data returned by the TBC which resides in the next 34 bytes and which should be the same as the host data.
Indication:
Indication returned by the TBC in full duplex loop back test. This value is 0 in the host interface test.
The following routine may be used to perform the host interface test:
Prepare the Initialization Table
Issue RESET command
Wait until Semaphore Register is 'FF'
Initialize the Interrupt Vector Register
Load the Function Code of the init table pointer into DRO
Issue LOAD INITIALIZATION TABLE FC Command
Wait until Semaphore Register is 'FF'
Load the Init Table Pointer into DR
Issue INITIALIZE Command
Issue SET MODE 3 Command to set SWAP and HLEN Bits
Prepare First 34 Bytes of Test Buffer
Load CPA VALO with Function Code of Buffer if Needed
Load CPA VAL 1 and CPA VAL2 with Pointer to Buffer
Clear Done Bit in CPA Status Word
Issue HOST INTERFACE TEST (Code is BC)
Wait for Done Bit in CPA Status Word
Compare Returned Data to Data which was given to the TBC
NOTE
In order to check for command completion, the host must clear the done bit in the CPA
status word before issuing a command to the TBC.
3.6.3 FULL-DUPLEX LOOPBACK TEST Command
The full-duplex loopback test checks the path from buffer memory through the TBC serial interface
and back to the memory buffer, thus checking ths proper functioning of the transmit and receive
MOTOROLA
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MC68824 USER'S MANUAL