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Programming the Ethernet controller (view source)
Revision as of 14:23, 19 July 2007
, 14:23, 19 July 2007no edit summary
** inouts
** inouts
*** ''AD'': 8-bit address and data bus
*** ''AD'': 8-bit address and data bus
=== (000) Reset Cycle ===
inputs
* State: 3-bit state value
* D_En: DAC enable, assume held high/low by previous block
* A_En: ADC enable, assume held high/low by previous block
* E_En: Ethernet enable, assume held high/low by previous block
internal signals
* S_En: state enable, S_En <= not (St(2) or St(1) or St(0))
* Go: when S_En goes high Go pulses for one cycle
* D_Go: DAC reset go pulse, D_Go <= Go and D_En
* A_Go: ADC reset go pulse, A_Go <= Go and A_En
* E_Go: Ethernet reset go pulse, E_Go <= Go and E_En
blocks
* DAC Reset:
** Resets and initializes the DAC.
** inputs
*** Clk: clock
*** /Rst: asynchronous, active-low reset
*** D_Go: go pulse to begin reset/initialization process
** outputs
*** - All DAC reset/initialization control lines -
*** D_Done: goes high when reset/initialization process is complete, falls on D_Go pulse
* ADC Reset:
** Resets and initializes the ADC.
** inputs
*** Clk: clock
*** /Rst: asynchronous, active-low reset
*** A_Go: go pulse to begin reset/initialization process
** outputs
*** - All ADC reset/initialization control lines -
*** A_Done: goes high when reset/initialization process is complete, falls on A_Go pulse
* Ethernet Reset:
** Resets and initializes the Ethernet controller.
** inputs
*** Clk: clock
*** /Rst: asynchronous, active-low reset
*** E_Go: go pulse to begin reset/initialization process
** outputs
*** - All Ethernet reset/initialization control lines -
*** E_Done: goes high when reset/initialization process is complete, falls on E_Go pulse
* Coordinator
** Coordinates the completion of each reset cycle and notifies other blocks that the reset process is complete. Has internal signal:
:Flag <= (D_Done or not D_En) and (A_Done or not A_En) and (E_Done or not E_En)
** inputs
*** Clk: clock
*** /Rst: asynchronous, active-low reset
*** D_En: high when DAC is to be reset
*** D_Done: high when DAC is done resetting
*** A_En: high when ADC is to be reset
*** A_Done: high when ADC is done resetting
*** E_En: high when Ethernet controller is to be reset
*** E_Done: high when Ethernet controller is done resetting
** outputs
*** Done: when Flag goes high, Done pulses for one cycle; connects to state counter as an enable (thereby incrementing the state to 001)