Pico-communications E-14 Manual do Utilizador descarregar pdf (Página 18)

E‐14HardwareReferenceManual www.picocomputing.com PicoComputing,Inc.







JTAGDebugInterface



ThePicoE‐14isequippedwithaJTAGdiagnosticportthatallowsreal‐timedebuggingofhardware,

firmwareandsoftware.UseoftheexternalJTAGportdisablesfourexternalGPIOpinsaswellasthe

internalJTAGloopback.



SomeJTAGprogramsrequirethelengthoftheinstructionregister(IR).TheIRlengthislistedbelowfor

alldevicesintheJTAGchain.



Device Instructionregisterbitlength

 FX20 FX60

FPGA 10 14

TurboLoader 8

EthernetPHY 8



FPGA

PowerPC

IR= 10

EthernetTurbo Loader

TDI TDO

IR= 8



Figure4



ThePrimaryImageintheFlashROMcontainsanembeddedJTAGdiagnosticport.Thisallowsauserin

WindowsorLinuxtodebugsoftwarewithoutanexternalJTAGcable.TheinternalJTAGdiagnosticloop

backlooksjustlikeaParallelPortIVdiagnosticcablewhenusedwiththePicoE‐14driver.



FX20: IR = 10

FX60: IR = 14

1 2 ... 13 14 15 16 17 18 19 20 21 22 23 ... 36 37

Sem comentários

Pico-communications E-14 Manual do Utilizador Página 18