Developing a bicycle speed-o-meter Part 2 A comparison between the Analog Devices ADSP-BF533 (Blackfin) and Motorola MC68332

General Project concept Blackfin Programmable Flag (PF) Input Magnetic Sensor Signal Motorola Parallel Interface Timer (PIT) Input High speed clock signal 4/25/2019 Motorola Blackfin Comparison Part 1 , Copyright M. Smith, ECE, University of Calgary, Canada

Main function concept ulong DetermineSpeed(ulong wheelDiameter, ulong clockFrequency) #define ulong unsigned long int; extern “C” ulong CountClockASM(const int); // Assembly code interface extern “C” ulong CalculateSpeedASM(ulong, ulong, ulong); extern “C” void SetupInterface(void); ulong DetermineSpeed(ulong wheelDiameter, ulong clockFrequency) { // Get to known position on magnetic sensor signal unsigned long discard_count; unsigned long count_high, count_low; SetupInterface( ); discard_count = CountClockASM(while_MagneticSensorHigh); discard_count = CountClockASM(while_MagneticSensorLow); count_high = CountClockASM(while_MagneticSensorHigh); count_low = CountClockASM(while_MagneticSensorLow); return CalculateSpeedASM(count_high + count_low, wheelDiameter, clockFrequency); } 4/25/2019 Motorola Blackfin Comparison Part 1 , Copyright M. Smith, ECE, University of Calgary, Canada

Required Assembly Language extern “C” ulong CountClockASM(const int); // Assembly code interface extern “C” void SetupInterface(void); extern “C” ulong CalculateSpeedASM(ulong, ulong, ulong); ulong CountClockASM(const int high_low) { ulong clock_count = 0; while (magnetic_sensor = = high_low) { // if signal is unchanged from start // Must count just one clock signal low-to-high transition while (clock_signal = = high) /* wait */; while (clock_signal = = low) /* wait */; // Changes on low-to-high edge clock_count++; } return clock_count; 4/25/2019 Motorola Blackfin Comparison Part 1 , Copyright M. Smith, ECE, University of Calgary, Canada

Programming model MC68332 Blackfin Data Registers D0, D1 …. D7 R0, R1 …. R7 Address Registers A0, A1 …. A6 Pointer Registers P0, P1 … P5 Frame Buffer Use A4 or A6 FP Stack Pointer SP (A7) SP Special DSP I0-I3, B0-B3, M0-M3, L0-L3 4/25/2019 Motorola Blackfin Comparison Part 1 , Copyright M. Smith, ECE, University of Calgary, Canada

Register to Register Move reg1  reg 2 32 bit operations Syntax examples MC68332 Blackfin Register to Register Move reg1  reg 2 32 bit operations MOVE.L D2, D1 R1 = R2; Memory Moves MOVE.L #MEM1, A0 MOVE.L #MEM2, A1 MOVE.B (A0), (A1) (8-bits) P0.H = hi(MEM1); P0.L = lo(MEM1); P1.H = hi(MEM2); P1.L = lo(MEM2); R0 =W [P0]; W[P1] = R0; 16-bits Set the condition code register CMP.L D0, D1 CC = D1 == D0; CC = D1 < D0; CC = D1 <= D0; Conditional jump BEQ NEXT_INSTR (D1 == D0) BLT NEXT_INSTR (D1 < D0) BLE NEXT_INSTR (D1 <= D0) IF CC JUMP NEXT_INSTR 4/25/2019 Motorola Blackfin Comparison Part 1 , Copyright M. Smith, ECE, University of Calgary, Canada

Example loop code -- software loop C++ example Motorola Blackfin sum = 0; for (loop = 0; loop < 6; loop++) sum = sum + loop; Set D0 = sum , D1 = loop MOVE.L #0, D0 MOVE.L #0, D1 LOOP: CMP.L #6, D1 BGE PAST_LOOP ADD.L D1, D0 ADD.L #1, D1 BRA LOOP PAST_LOOP: Set R0 = sum , R1 = loop R0 = 0; R1 = 0; R2 = 6; LOOP: CC = R2 <= R1; IF !CC JUMP PAST_LOOP; R0 = R0 + R1; R1 += 1; JUMP LOOP 4/25/2019 Motorola Blackfin Comparison Part 1 , Copyright M. Smith, ECE, University of Calgary, Canada

Hardware test – wait while magnetic signal is “high” Motorola Blackfin Magnetic Signal Bit 1 of PADR register of PI/T interface Bit 10 of FIO_FLAG_D register of PF interface while (mag_signal == HIGH) /* wait */ ; MASK EQU 0x1 MOVE.L #PITBASE, A0 WHILE: MOVE.B PADR(A0), D0 AND.B #MASK, D0 CMP.B #MASK, D0 BEQ WHILE #define MASK 0x400 P0.H = hi(FIO_FLAG_D); P0.L = lo(FIO_FLAG_D); R1 = MASK; R0 = W[P0] (Z); R0 = R0 & R1; CC = R0 == R1; IF CC JUMP WHILE (BP); 4/25/2019 Motorola Blackfin Comparison Part 1 , Copyright M. Smith, ECE, University of Calgary, Canada

Required 68K Assembly Language _CountClockASM: MOVEA.L #0, A1 // Use as counter MOVEA.L #PITBASE, A0 MOVE.L 4(SP), D0 WHILE: MOVE.B PADR(A0), D1 AND.B #MASKMAG, D1 CMP.B D0, D1 BNE END_WHILE HIGH: MOVE.B PADR(A0), D1 AND.B #MASKCLK, D1 BNE HIGH LOW: MOVE.B PADR(A0), D1 AND.B #MASKCLK, D1 BEQ LOW ADDA.L #1, A1 BRA WHILE END_WHILE: MOVE.L A1, D0 RTS ulong CountClockASM(const int high_low) { ulong clock_count = 0; while (magnetic_sensor = = high_low) { // if signal is unchanged from start // Must count just one clock signal // low-to-high transition while (clock_signal = = high) /* wait */; while (clock_signal = = low) /* wait */; // Changes on low-to-high edge clock_count++; } return clock_count; 4/25/2019 Motorola Blackfin Comparison Part 1 , Copyright M. Smith, ECE, University of Calgary, Canada

Required BF533 Assembly Language _CountClockASM: R0 contains the INPAR R1 = 0; P0.H = hi(FIO_FLAG_D); P0.L = lo(FIO_FLAG_D); WHILE: R2 = W[P0] (Z); R3 = MASKMAG; R2 = R2 & R3; CC = R2 == R0; IF !CC JUMP ENDWHILE; R3 = MASKCLK; HIGH: R2 = W[P0] (Z); CC = R2 == R3 IF CC JUMP HIGH (BP); LOW : R2 = W[P0] (Z); CC = R2 < R3 IF CC JUMP LOW (BP); R1 += 1; JUMP WHILE END_WHILE: R0 = R1; RTS ulong CountClockASM(const int high_low) { ulong clock_count = 0; while (magnetic_sensor = = high_low) { // if signal is unchanged from start // Must count just one clock signal // low-to-high transition while (clock_signal = = high) /* wait */; while (clock_signal = = low) /* wait */; // Changes on low-to-high edge clock_count++; } return clock_count; 4/25/2019 Motorola Blackfin Comparison Part 1 , Copyright M. Smith, ECE, University of Calgary, Canada

Compare 68K and Blackfin 4/25/2019 _CountClockASM: R0 contains the INPAR R1 = 0; P0.H = hi(FIO_FLAG_D); P0.L = lo(FIO_FLAG_D); WHILE: R2 = W[P0] (Z); R3 = MASKMAG; R2 = R2 & R3; CC = R2 == R0; IF !CC JUMP ENDWHILE; R3 = MASKCLK; HIGH: R2 = W[P0] (Z); CC = R2 == R3 IF CC JUMP HIGH (BP); LOW : R2 = W[P0] (Z); CC = R2 < R3 IF CC JUMP LOW (BP); R1 += 1; JUMP WHILE END_WHILE: R0 = R1; RTS _CountClockASM: MOVEA.L #0, A1 // Use as counter MOVEA.L #PITBASE, A0 MOVE.L 4(SP), D0 WHILE: MOVE.B PADR(A0), D1 AND.B #MASKMAG, D1 CMP.B D0, D1 BNE END_WHILE HIGH: MOVE.B PADR(A0), D1 AND.B #MASKCLK, D1 BNE HIGH LOW: MOVE.B PADR(A0), D1 AND.B #MASKCLK, D1 BEQ LOW ADDA.L #1, A1 BRA WHILE END_WHILE: MOVE.L A1, D0 RTS 4/25/2019 Motorola Blackfin Comparison Part 1 , Copyright M. Smith, ECE, University of Calgary, Canada

Subroutine / Function calls Motorola Blackfin extern “C” int FooASM(int, int, int) C = FooASM(1,2,3) .IMPORT _FooASM FP EQU A6 LINK FP, -16 MOVE.L D4, 12(SP) MOVE.L #1, 0(SP) MOVE.L #2, 4(SP) MOVE.L #3, 8(SP) JSR _FooASM MOVE.L D0, D4 .. Other code MOVE.L 12(SP), D4 UNLINK RTS .extern _FooASM LINK 20; [SP + 16] = R4; R0 = 1; R1 = 2; R2 = 3; CALL _FooASM; R4 = R0; R4 = [SP + 16]; UNLINK; RTS; 4/25/2019 Motorola Blackfin Comparison Part 1 , Copyright M. Smith, ECE, University of Calgary, Canada

Code conventions for subroutines / functions Motorola -- SDS Blackfin -- VisualDSP Volatile registers D0, D1 A0, A1 R0, R1, R2, R3 P0, P1, P2 Non-volatile registers D2, D2, D4, D5, D6, D7 A2, A3, A4, A5, A6, A7 R4, R5, R6, R7 P3, P4, P5, FP, SP Subroutine return value is passed in D0 R0 Subroutine OUTPARS OUTPAR1  0(SP) OUTPAR2  4(SP) OUTPAR3  8(SP) OUTPAR4  12(SP) OUTPAR1  R0 OUTPAR2  R1 OUTPAR3  R2 4/25/2019 Motorola Blackfin Comparison Part 1 , Copyright M. Smith, ECE, University of Calgary, Canada

Main 68K function concept _DetermineSpeed: LINK A6, -16 MOVE.L D4, 12(SP) JSR _SetupInterface MOVE.L #MASKMAG, 0(SP) JSR _CountClockASM MOVE.L #0, 0(SP) JSR _CountClockASM MOVE.L #MASKMAG, 0(SP) JSR _CountClockASM MOVE.L D0, D4 ; count_high MOVE.L #0, 0(SP) JSR _CountClockASM ADD.L D0, D4 ; high + low. MOVE.L D4, 0(SP) MOVE.L 8(FP), 4(SP) MOVE.L 12(FP), 8(SP) JSR _CalculateSpeedASM ; Return in D0 MOVE.L 12(SP), D4 UNLINK A6 RTS ulong DetermineSpeed(ulong wheelDiameter, ulong clockFrequency) { // Get to known position on magnetic sensor signal unsigned long discard_count; unsigned long count_high, count_low; SetupInterface( ); discard_count = CountClockASM(while_MagneticSensorHigh); discard_count = CountClockASM(while_MagneticSensorLow); count_high = CountClockASM(while_MagneticSensorHigh); count_low = CountClockASM(while_MagneticSensorLow); return CalculateSpeedASM(count_high + count_low, wheelDiameter, clockFrequency); } 4/25/2019 Motorola Blackfin Comparison Part 1 , Copyright M. Smith, ECE, University of Calgary, Canada

Main Blackfin function concept _DetermineSpeed: LINK 20 [FP + 8] = R0; [FP + 12] = R1; // Save INPARS [SP + 16] = R4; CALL _SetupInterface; R0 = MASKMAG; CALL _CountClockASM; R0 = 0; CALL _CountClockASM R4 = R0; // count_high R0 = R0 + R4; // high + low. R1 = [FP + 8]; // old INPAR1 R2 = [FP + 12]; // old INPAR2 CALL _CalculateSpeedASM // Return in R0 [SP + 16] = R4; UNLINK RTS ulong DetermineSpeed(ulong wheelDiameter, ulong clockFrequency) { // Get to known position on magnetic sensor signal unsigned long discard_count; unsigned long count_high, count_low; SetupInterface( ); discard_count = CountClockASM(while_MagneticSensorHigh); discard_count = CountClockASM(while_MagneticSensorLow); count_high = CountClockASM(while_MagneticSensorHigh); count_low = CountClockASM(while_MagneticSensorLow); return CalculateSpeedASM(count_high + count_low, wheelDiameter, clockFrequency); } 4/25/2019 Motorola Blackfin Comparison Part 1 , Copyright M. Smith, ECE, University of Calgary, Canada

Compare 68K and Blackfin _DetermineSpeed: LINK 20 [FP + 8] = R0; [FP + 12] = R1; // Save INPARS [SP + 16] = R4; CALL _SetupInterface; R0 = MASKMAG; CALL _CountClockASM; R0 = 0; CALL _CountClockASM R4 = R0; // count_high R0 = R0 + R4; // high + low. R1 = [FP + 8]; // old INPAR1 R2 = [FP + 12]; // old INPAR2 CALL _CalculateSpeedASM // Return in R0 [SP + 16] = R4; UNLINK RTS _DetermineSpeed: LINK A6, -16 MOVE.L D4, 12(SP) JSR _SetupInterface MOVE.L #MASKMAG, 0(SP) JSR _CountClockASM MOVE.L #0, 0(SP) JSR _CountClockASM MOVE.L #MASKMAG, 0(SP) JSR _CountClockASM MOVE.L D0, D4 ; count_high MOVE.L #0, 0(SP) JSR _CountClockASM ADD.L D0, D4 ; high + low. MOVE.L D4, 0(SP) MOVE.L 8(FP), 4(SP) MOVE.L 12(FP), 8(SP) JSR _CalculateSpeedASM ; Return in D0 MOVE.L 12(SP), D4 UNLINK A6 RTS 4/25/2019 Motorola Blackfin Comparison Part 1 , Copyright M. Smith, ECE, University of Calgary, Canada

extern “C” void SetupInterface(void); Motorola Blackfin Direction register 0 = input, 1 = output PADDR 8-bits FIO_DIR 16-bits Interrupt control bits in PACR, PGCR control H1, H2 FIO_MASKA_D on any bit Enable input (Power save issue) FIO_INEN on any bit Polarity bits in PGCR control H1, H2 FIO_POLAR on any bit Edge / Level sensitivity FIO_EDGE FIO_BOTH on any bit Magnetic signal Clock signal Bit 0 MASKMAG 0x1 Bit 1 MASKCLK 0x2 Bit 10 MASKMAG 0x200 Bit 11 MASKCLK 0x400 4/25/2019 Motorola Blackfin Comparison Part 2 , Copyright M. Smith, ECE, University of Calgary, Canada

extern “C” void SetupInterface(void); SPECIFICS Motorola Blackfin Magnetic signal Clock signal Bit 0 MASKMAG 0x1 Bit 1 MASKCLK 0x2 Bit 10 MASKMAG 0x200 Bit 11 MASKCLK 0x400 Direction register 0 = input, 1 = output D0  PADDR MASK OFF BITS 1, 0 PADDR  D0 R0  FIO_DIR MASK OFF BITS 10, 11 FIO_DIR  R0 Interrupt control bits in PACR, PGCR control H1, H2 R0  FIO_MASKA_D MASK OFF BITS 10, 11 FIO_MASKA_D  R0 Enable input (Power save issue) R0  FIO_INEN OR BITS 10, 11 FIO_INEN  R0 Polarity bits in PGCR control H1, H2 R0  FIO_POLAR MASK OFF BITS 10, 11 FIO_POLAR  R0 Edge / Level sensitivity FIO_EDGE FIO_BOTH MASK OFF BITS 10, 11 4/25/2019 Motorola Blackfin Comparison Part 2 , Copyright M. Smith, ECE, University of Calgary, Canada

In class exercise – Write 68K code for extern “C” void SetupInterface(void); 4/25/2019 Motorola Blackfin Comparison Part 1 , Copyright M. Smith, ECE, University of Calgary, Canada

In class exercise – Write Blackfin code for extern “C” void SetupInterface(void); 4/25/2019 Motorola Blackfin Comparison Part 1 , Copyright M. Smith, ECE, University of Calgary, Canada

Information taken from Analog Devices On-line Manuals with permission http://www.analog.com/processors/resources/technicalLibrary/manuals/ Information furnished by Analog Devices is believed to be accurate and reliable. However, Analog Devices assumes no responsibility for its use or for any infringement of any patent other rights of any third party which may result from its use. No license is granted by implication or otherwise under any patent or patent right of Analog Devices. Copyright  Analog Devices, Inc. All rights reserved. 4/25/2019 Motorola Blackfin Comparison Part 1 , Copyright M. Smith, ECE, University of Calgary, Canada