IEEE 802.3u Ethernet 1995 . MII (Media Independent Interface , ), (PHY) . MII SMI (Serial Management Interface), PHY. PHY ; , . , , , . SMI ( MDC, MDIO GND), 16- . 5- , 32 . 32 . - , , . MDC, MDIO ( ) . , , . ; MDIO () , (+5 +3,3 ). MDC, , 2,5 , . ́́ . 11.4. , MDC, . .
. 11.4. SMI: a ,
Pre 32 MDIO . Start 01, Cmd: 10 01 . 5- (PhyAd), 5- (RegAd). (turnaround) . 10, 16 (WData) . MDIO, , . 16 (RData) .
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( ); , . : 1 .
SPI
SPI (Serial Peripheral Interface), Microwire, . (, FPGA Altera), . I²C SPI . 5 ( ); , . , . , , . . 3 :
♦ SCK (Serial Clock) , ;
♦ MOSI (Master Output Slave Input) ;
♦ MISO (Master Input Slave Output) .
, SS# (Slave Select, CS# Chip Select): MISO ; MISO . SS#, , . : SCK, MOSI MISO , SS# ( ).
. SS# , , . , , MISO . .
. (SPI Mode 0SPI Mode 3), . . 11.5 . , . , SS#. ( ) SS#, . () SCK, SS# . , . SPI, , . , : MOSI ; . , MISO. SS#, .
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. 11.5. SPI
JTAG
JTAG (Joint Test Action Group) , . IEEE 1149.1 Boundary Scan Architecture , , . JTAG - ( ), . JTAG.
♦ TCK (Test Clock) ; . 16 .
♦ TMS (Test Mode Select) . .
♦ TDI (Test Data Input) , ( ).
♦ TDO (Test Data Output) , .
♦ TRST (Test Logic Reset) , .
( ), , TAP (Test Access Port), (). , , . , JTAG. TAP (. 11.6). ( , , JTAG).
. 11.6. JTAG
. 11.7, , , (, ) . B/S , (boundary) . TAP- . Boundary Scan, . TAP- , , , ( ). JTAG , , .
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. 11.7.
, , JTAG, :
♦ TAP ( );
♦ TAP-, ;
♦ IR (Instruction Register), TDI ( , );
♦ , : PR (Bypass Register), DID (Device Identification Register) BSR (Boundary Scan Register).
, . ( ) TDI, ( ) TDO. .
R . , .
BSR , , . ( ), , , , . , P6 BSR 159 .
DID 32 , , TAP- , .
IR . . BYPASS, IDCODE, SAMPLE EXTEST.
BYPASS ( ) , ; . TDI , JTAG . .
IDCODE ( 10) DID, ( ).
SAMPLE/PRELOAD ( 01) . TAP- Capture-DR (. ), . TCK. Update-DR ( ), ( ) EXTEST. TCK.
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EXTEST ( 00) ( ). , BSR, . BSR.
1149.1 INTEST, .
(TAP-controller) , TCK . TMS (Test Mode State), TCK. . 11.8. TMS TCK.
. 11.8. TAP
Test-Logic-Reset TMS, TCK. Test-Logic-Reset TRST. , .
Run-Test/Idle . .
Capture-DR EXTEST SAMPLE/PRELOAD .
Shift-DR TDI TDO.
Pause-DR .
Update-DR TCK .
Capture-IR SAMPLE.
Shift-IR TDI TDO , .
Pause-IR .
Update-IR TCK , TDI-TDO .
, , , . Select-DR-Scan, Exit1-DR, Exit2-DR, Select-DR-Scan, Exit1-IR Exit2-IR.
JTAG BSDL (Boundary Scan Description Language). ( ) .
JTAG , , . JTAG PCI, ( , ). JTAG ; ( ), (probe mode, . [6, 7]). ; , JTAG, .