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Programming the Ethernet controller (view source)
Revision as of 17:59, 14 November 2007
, 17:59, 14 November 2007→(010) Idle
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* ''TxRx_A'': 8-bit address from transceiver+
internal signals
−* ''S_En'': state enable, ''S_En'' <= not ''St(2)'' and ''St(1)'' and not ''St(0)''
−* ''Go'': when ''S_En'' goes high ''Go'' pulses for one cycle
** Reads register 0x76 (INT0RD) by sending a read request to the transceiver
−** inputs
−*** ''F_Go'': pulse to start request, ''F_Go'' <= ''Go'' or ''Loop''
−** outputs
−*** ''TxRx_Go'': ''Go'' line on transceiver
−*** ''TxRx_R/W'': ''R/W'' line on transceiver, tied high (read)
−*** ''TxRx_A'': ''A_in'' bus on transceiver, tied to 0x76 (0111 0110)
−**** Note: ''D_in'' on transceiver is not used; assume this line defaults to zero
* ''Clk'': clock
* ''Clk'': clock
* ''/Rst'': asynchronous, active-low reset
* ''/Rst'': asynchronous, active-low reset
−* ''State'': 3-bit state value
+* ''state_in'': 3-bit state value
−* ''TxRx_D'': 8-bit data from transceiver
* ''TxRx_D'': 8-bit data from transceiver
* ''TxRx_Done'': pulse from transceiver to signal transfer complete
* ''TxRx_Done'': pulse from transceiver to signal transfer complete
+* ''TxRx_Go'': transceiver go line
+* ''TxRx_R/W'': read/write flag for transceiver
+* ''TxRx_Aout'': register address bus for transceiver
+
−blocks
blocks
−* '''Fetcher'''
+* '''Register INT0RD (0x76)''' request via <tt>reqFromAddr</tt> pulsed by the ''LoopEn'' signal from Looper (below).
−* '''Looper'''
* '''Looper'''
** Switch to determine if this state should loop on itself or continue to the next state.
** Switch to determine if this state should loop on itself or continue to the next state.
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*** ''TxRx_Data'': ''D_out'' bus from transceiver
*** ''TxRx_Data'': ''D_out'' bus from transceiver
** outputs
** outputs
−*** ''Loop'': pulse to repeat fetch cycle; ''Loop'' <= ''S_En'' and ''TxRx_Done'' and ''TxRx_Data(6)''
+*** ''LoopEn'': pulse to repeat fetch cycle; ''Loop'' <= ''S_En'' and ''TxRx_Done'' and ''TxRx_Data(6)''
*** ''Done'': pulse to finish state; connects to state counter as an enable; ''Done'' <= ''S_En'' and ''TxRx_Done'' and not ''TxRx_Data(6)''
*** ''Done'': pulse to finish state; connects to state counter as an enable; ''Done'' <= ''S_En'' and ''TxRx_Done'' and not ''TxRx_Data(6)''
*** ''New_St'': new state value to load into state register; goes to 011 when ''Done'' is high
*** ''New_St'': new state value to load into state register; goes to 011 when ''Done'' is high