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Broddo's avatar
Broddo
Icon for Occasional Contributor rankOccasional Contributor
6 months ago

NIOSV/g with FPU: inconsistent calculation results

I'm using a NIOSV/g with FPU enabled in a MAX10 project. The project involves heavy use of float point calculations, hence the need for the FPU. I noticed some occasionally inconsistent results in th...
Nios Architecture
LYGOOI's avatar
LYGOOI
Icon for New Contributor rankNew Contributor
5 months ago

Hi @Broddo

Can you share your processor IP Parameter Editor settings?

And which Quartus version is your design based on?


Or, you can zip the design & attach it in your next reply.

Regards,

Liang Yu

Broddo's avatar
Broddo
Icon for Occasional Contributor rankOccasional Contributor
5 months ago

Thanks for the reply @LYGOOI and apologies for the delay in getting back to you - I was on vacation.

To answer your questions: I'm using Quartus Lite 24.1 and I've pasted the CPU parameters below.

I've attached the test project that builds all of this. I'm running on a custom board (that was previously running a NIOS2 application with no issues). If you want to run it yourself, the only change you'll have to make is the location of the source clock.

For convenience, I've added a Makefile that will build the project and the software - you'll see for yourself.

Here are the CPU parameters

<module
   name="intel_niosv_g_0"
   kind="intel_niosv_g"
   version="4.0.0"
   enabled="1">
  <parameter name="AUTO_CLK_CLOCK_DOMAIN" value="3" />
  <parameter name="AUTO_CLK_RESET_DOMAIN" value="3" />
  <parameter name="AUTO_DEVICE" value="10M50DAF484C8G" />
  <parameter name="AUTO_DEVICE_SPEEDGRADE" value="8" />
  <parameter name="Blind_Window_Period" value="1000" />
  <parameter name="CLICenabledInterruptMode" value="0" />
  <parameter name="CLICenabledShadowRegisterFiles" value="1" />
  <parameter name="CUSTOM_OP" value="" />
  <parameter name="Default_Timeout_Period" value="255" />
  <parameter name="SUB_OP" value="" />
  <parameter name="alignCLICVectorTable" value="8" />
  <parameter name="basicInterruptMode" value="0" />
  <parameter name="basicShadowRegisterFiles" value="0" />
  <parameter name="clockFrequency" value="75000000" />
  <parameter name="dataCacheSize" value="4096" />
  <parameter name="dataSlaveMapParam"><![CDATA[<address-map><slave name='onchip_flash.data' start='0x0' end='0x160000' type='altera_onchip_flash.data' /><slave name='onchip_memory.s1' start='0x200000' end='0x214000' type='altera_avalon_onchip_memory2.s1' /><slave name='intel_niosv_g_0.dm_agent' start='0x220000' end='0x230000' type='intel_niosv_g.dm_agent' /><slave name='intel_niosv_g_0.timer_sw_agent' start='0x230000' end='0x230040' type='intel_niosv_g.timer_sw_agent' /><slave name='jtag_uart_0.avalon_jtag_slave' start='0x230040' end='0x230048' type='altera_avalon_jtag_uart.avalon_jtag_slave' /><slave name='onchip_flash.csr' start='0x230048' end='0x230050' type='altera_onchip_flash.csr' /></address-map>]]></parameter>
  <parameter name="deviceFamily" value="MAX 10" />
  <parameter name="disableFsqrtFdiv" value="false" />
  <parameter name="dtcm1Base" value="18874368" />
  <parameter name="dtcm1InitFile" value="" />
  <parameter name="dtcm1Size" value="0" />
  <parameter name="dtcm2Base" value="0" />
  <parameter name="dtcm2InitFile" value="" />
  <parameter name="dtcm2Size" value="0" />
  <parameter name="enableBranchPrediction" value="true" />
  <parameter name="enableCLICInterruptEdgeTriggerConfig" value="false" />
  <parameter name="enableCLICInterruptPolarityConfig" value="false" />
  <parameter name="enableCLICSelectiveHardwareVectoring" value="false" />
  <parameter name="enableCoreLevelInterruptController" value="false" />
  <parameter name="enableDebug" value="true" />
  <parameter name="enableDebugReset" value="true" />
  <parameter name="enableECCFull" value="false" />
  <parameter name="enableECCLite" value="false" />
  <parameter name="enableFPU" value="true" />
  <parameter name="enableLockstep" value="false" />
  <parameter name="enableLockstepExtRst" value="false" />
  <parameter name="enableMulDiv" value="true" />
  <parameter name="funct3" value="" />
  <parameter name="funct7_l" value="" />
  <parameter name="funct7_u" value="" />
  <parameter name="hartId" value="0" />
  <parameter name="instCacheSize" value="4096" />
  <parameter name="instSlaveMapParam"><![CDATA[<address-map><slave name='onchip_flash.data' start='0x0' end='0x160000' type='altera_onchip_flash.data' /><slave name='onchip_memory.s1' start='0x200000' end='0x214000' type='altera_avalon_onchip_memory2.s1' /><slave name='intel_niosv_g_0.dm_agent' start='0x220000' end='0x230000' type='intel_niosv_g.dm_agent' /></address-map>]]></parameter>
  <parameter name="itcm1Base" value="19922944" />
  <parameter name="itcm1InitFile" value="" />
  <parameter name="itcm1Size" value="0" />
  <parameter name="itcm2Base" value="0" />
  <parameter name="itcm2InitFile" value="" />
  <parameter name="itcm2Size" value="0" />
  <parameter name="mnemonic" value="" />
  <parameter name="numCLICDebugTriggers" value="0" />
  <parameter name="numCLICLevels" value="2" />
  <parameter name="numCLICPlatformInterrupts" value="16" />
  <parameter name="numCLICPriorities" value="8" />
  <parameter name="opcode" value="" />
  <parameter name="peripheralRegionABase" value="2293760" />
  <parameter name="peripheralRegionASize" value="65536" />
  <parameter name="peripheralRegionBBase" value="67108864" />
  <parameter name="peripheralRegionBSize" value="2097152" />
  <parameter name="resetOffset" value="0" />
  <parameter name="resetSlave" value="onchip_flash.data" />
  <parameter name="useResetReq" value="false" />
 </module>