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-- memory block to the CRC processor
-- see the STM32Cube_FW_F4_V1.6.0\Projects\ CRC example for data and
-- expected CRC checksum value
Section1 : constant Block_32 :=
(16#00001021#, 16#20423063#, 16#408450A5#, 16#60C670E7#, 16#9129A14A#, 16#B16BC18C#,
16#D1ADE1CE#, 16#F1EF1231#, 16#32732252#, 16#52B54294#, 16#72F762D6#, 16#93398318#,
16#A35AD3BD#, 16#C39CF3FF#, 16#E3DE2462#, 16#34430420#, 16#64E674C7#, 16#44A45485#,
16#A56AB54B#, 16#85289509#, 16#F5CFC5AC#, 16#D58D3653#, 16#26721611#, 16#063076D7#,
16#569546B4#, 16#B75BA77A#, 16#97198738#, 16#F7DFE7FE#, 16#C7BC48C4#, 16#58E56886#,
16#78A70840#, 16#18612802#, 16#C9CCD9ED#, 16#E98EF9AF#, 16#89489969#, 16#A90AB92B#,
16#4AD47AB7#, 16#6A961A71#, 16#0A503A33#, 16#2A12DBFD#, 16#FBBFEB9E#, 16#9B798B58#,
16#BB3BAB1A#, 16#6CA67C87#, 16#5CC52C22#, 16#3C030C60#, 16#1C41EDAE#, 16#FD8FCDEC#,
16#AD2ABD0B#, 16#8D689D49#, 16#7E976EB6#, 16#5ED54EF4#, 16#2E321E51#, 16#0E70FF9F#);
Section2 : constant Block_32 :=
(16#EFBEDFDD#, 16#CFFCBF1B#, 16#9F598F78#, 16#918881A9#, 16#B1CAA1EB#, 16#D10CC12D#,
16#E16F1080#, 16#00A130C2#, 16#20E35004#, 16#40257046#, 16#83B99398#, 16#A3FBB3DA#,
16#C33DD31C#, 16#E37FF35E#, 16#129022F3#, 16#32D24235#, 16#52146277#, 16#7256B5EA#,
16#95A88589#, 16#F56EE54F#, 16#D52CC50D#, 16#34E224C3#, 16#04817466#, 16#64475424#,
16#4405A7DB#, 16#B7FA8799#, 16#E75FF77E#, 16#C71DD73C#, 16#26D336F2#, 16#069116B0#,
16#76764615#, 16#5634D94C#, 16#C96DF90E#, 16#E92F99C8#, 16#B98AA9AB#, 16#58444865#,
16#78066827#, 16#18C008E1#, 16#28A3CB7D#, 16#DB5CEB3F#, 16#FB1E8BF9#, 16#9BD8ABBB#,
16#4A755A54#, 16#6A377A16#, 16#0AF11AD0#, 16#2AB33A92#, 16#ED0FDD6C#, 16#CD4DBDAA#,
16#AD8B9DE8#, 16#8DC97C26#, 16#5C644C45#, 16#3CA22C83#, 16#1CE00CC1#, 16#EF1FFF3E#,
16#DF7CAF9B#, 16#BFBA8FD9#, 16#9FF86E17#, 16#7E364E55#, 16#2E933EB2#, 16#0ED11EF0#);
-- expected CRC value for the data above is 379E9F06 hex, or 933142278 dec
Expected_Checksum : constant UInt32 := 933142278;
Next_DMA_Interrupt : DMA_Interrupt;
procedure Panic with No_Return;
-- flash the on-board LEDs, indefinitely, to indicate a failure
procedure Panic is
begin
loop
Toggle_LEDs (All_LEDs);
delay until Clock + Milliseconds (100);
end loop;
end Panic;
begin
Clear_Screen;
Initialize_LEDs;
Enable_Clock (CRC_Unit);
-- get the checksum using the CPU to transfer memory to the CRC processor;
-- verify it is the expected value
Update_CRC (CRC_Unit, Input => Section1, Output => Checksum_CPU);
Update_CRC (CRC_Unit, Input => Section2, Output => Checksum_CPU);
Put_Line ("CRC:" & Checksum_CPU'Img);
if Checksum_CPU /= Expected_Checksum then
Panic;
end if;
-- get the checksum using DMA to transfer memory to the CRC processor
Enable_Clock (Controller);
Reset (Controller);
Reset_Calculator (CRC_Unit);
Update_CRC (CRC_Unit, Controller'Access, Stream, Input => Section1);
DMA_IRQ_Handler.Await_Event (Next_DMA_Interrupt);
if Next_DMA_Interrupt /= Transfer_Complete_Interrupt then
Panic;
end if;
-- In this code fragment we use the approach suited for the case in which
-- we are calculating the CRC for a section of system memory rather than a
-- block of application data. We pretend that Section2 is a memory section.
-- All we need is a known starting address and a known length. Given that,
-- we can create a view of it as if it is an object of type Block_32 (or
-- whichever block type is appropriate).
declare
subtype Memory_Section is Block_32 (1 .. Section2'Length);
type Section_Pointer is access all Memory_Section with Storage_Size => 0;
function As_Memory_Section_Reference is new Ada.Unchecked_Conversion
(Source => System.Address, Target => Section_Pointer);
begin
Update_CRC
(CRC_Unit,
Controller'Access,
Stream,
Input => As_Memory_Section_Reference (Section2'Address).all);
Function Definition: procedure DSB is
Function Body: begin
Asm ("dsb", Volatile => True);
end DSB;