Logbook of Martin

From a software perspective, NEON technology is based on single instruction, multiple data (SIMD) operations in ARMv7 processors, which implement the advanced SIMD architecture extensions. From a hardware perspective, NEON is a separate hardware unit on Cortex-A series processors, together with a vector floating point (VFP) unit. If an algorithm can be designed to exploit dedicated hardware, performance can be maximized. SIMD Introduction SIMD is a computational technique for processing many data values in parallel using a single instruction, with the data for the operands packed into special, wide registers. Therefore, one instruction can do the work of many separate instructions on single instruction, single data (SISD) architectures. Many software programs operate on large data sets. Each element in a data set can be less than 32 bits. 8-bit data is common in video, graphics, and image processing, and 16-bit data in audio codecs. In these contexts, the operations ...

Xilinx Application Note : xapp1206 將-mfpu= vfpv3  -mfloat-abi= hard (default)設定成 -mfpu= neon  -mfloat-abi= softfp 會出現下列錯誤訊息 solution: step1: C/C++ Build -> Settings -> Tool Settings ARM v7 gcc compiler -> Miscellaneous Linker Flags : -c -fmessage-length=0 -MT"$@" -mcpu=cortex-a9 -mfpu= neon -mfloat-abi= softfp ARM v7 gcc linker -> Miscellaneous Linker Flags : -mcpu=cortex-a9 -mfpu= neon -mfloat-abi= softfp -Wl,-build-id=none -specs=Xilinx.spec step2 :  Modify this BSP’s Settings -> Overview -> Drivers -> ps7_cortexa9_0 Extra_compiler_flags : -mcpu=cortex-a9 -mfpu= neon -mfloat-abi= softfp -nostartfiles -Wall -Wextra

Solution The math "m" option needs to be specified in the Libraries in the C/C++ Build Settings. ref : https://www.xilinx.com/support/answers/52971.html

The reset system includes resets generated by hardware, watchdog timers, the JTAG controller, and software. Every module and system in Zynq-7000 AP SoC devices includes a reset that is driven by the reset system. Hardware resets are driven by the power-on reset signal (PS_POR_B) and the system reset signal (PS_SRST_B). The user can reset the entire system by asserting a software reset. By asserting PSS_RST_CTRL[SOFT_RST], the entire system is reset with the same end result as the user pressing the PS_SRST_B pin (other than the REBOOT_STATUS register value being different). Just like the other system resets, all of the RAMs are cleared and the PL is reset as well. Related register : SLCR_LOCK Relative Address : 0x00000004 Absolute Address : 0xF8000004 Width : 32 bits Access Type : wo Reset Value : 0x00000000 Description : SLCR Write Protection Lock SLCR_UNLOCK Relative Address : 0x00000008 Absolute Address : 0xF8000008 Width : 32 bits Access Type...