Smart Snippets Command-line read flash problem

Hi, Dialog Support Team:
I am using DA14581,external flash,MX25V1006F,1M-BIT [x 1/x 2] CMOS SERIAL NOR FLASH. and when I use Smart Snippets Command-line (Vesion 3.9) to download my hex file(30716 bytes), it shows that "Communication timed out: Requested 6144 bytes, received 0 bytes !". But it can dowload sucessfully when i use Smart Snippets with UI.
I alse discover a very weird phenomenon.when I use Smart Snippets Command-line to read 30716 bytes flash, it shows the same error, even if the flash has been erased. But when it can read 30717 bytes flash sucessfully,or other length, not 30716 bytes.
when i use Smart Snippets with UI to download hex file,it read 32kB to verify. when I use Smart Snippets Command-line,it read the same size of hex file(30716 bytes).But why can't read 30716 bytes with Smart Snippets Command-line.
I spy the data in SPI line when it read 30716 bytes with Smart Snippets Command-line.There is absolutely right.

The following is the log.Please help me analyze the problem,thanks a lot.
******************************************
命令行：smartsnippets.exe -type spi -chip da14581-clk p0_0 -cs p0_4 -miso p0_5-mosi p0_6 -jtag 325235 -firmware jtag_programmer.bin -cmd写-gpio p1_2 -file。\ ble.hex -y -verify
log:
Could not measure total IR len. TDO is constant high.
Could not measure total IR len. TDO is constant high.
Found SWD-DP with ID 0x0BB11477
FPUnit: 4 code (BP) slots and 0 literal slots
Found Cortex-M0 r0p0, Little endian.
BTLE device selected.
Firmware File jtag_programmer.bin has been selected for downloading.
Successfully downloaded firmware file to the board.
Using default baudrate: 57600 Bd.
Successfully set SPI Flash gpios: CLK=P0_0, CS=P0_4, MISO=P0_5, MOSI=P0_6.
Read 30412 bytes from file .\ble.hex.
Started burning memory with 30716 bytes of data at address 0x00008.
Memory burning completed successfully.
读取内存以验证其内容刻录后....
通信超时：请求6144字节，收到0字节！
Failed reading memory at address 20000000.
******************************************
******************************************
命令行：smartsnippets.exe -type spi -chip da14581-clk p0_0 -cs p0_4 -miso p0_5 -mosi p0_6 -jtag 325235 -firmware jtag_programmer.bin -cmd read-gpio p1_2 -file flash.hex -length 30716 -y
log:
Found SWD-DP with ID 0x0BB11477
FPUnit: 4 code (BP) slots and 0 literal slots
Found Cortex-M0 r0p0, Little endian.
BTLE device selected.
Firmware File jtag_programmer.bin has been selected for downloading.
Successfully downloaded firmware file to the board.
Using default baudrate: 57600 Bd.
Successfully set SPI Flash gpios: CLK=P0_0, CS=P0_4, MISO=P0_5, MOSI=P0_6.
Started reading 30716 bytes from SPI FLASH offset 0x0.
通信超时：请求6144字节，收到0字节！
Failed reading memory at address 20000000.
SPI FLASH memory reading has failed.
******************************************
******************************************
Command-line:SmartSnippets.exe -type spi -chip DA14581 -clk P0_0 -cs P0_4 -miso P0_5 -mosi P0_6 -jtag 325235 -firmware jtag_programmer.bin -cmd read -gpio P1_2 -file flash.hex -length 30717 -y
log:
Found SWD-DP with ID 0x0BB11477
FPUnit: 4 code (BP) slots and 0 literal slots
Found Cortex-M0 r0p0, Little endian.
BTLE device selected.
Firmware File jtag_programmer.bin has been selected for downloading.
Successfully downloaded firmware file to the board.
Using default baudrate: 57600 Bd.
Successfully set SPI Flash gpios: CLK=P0_0, CS=P0_4, MISO=P0_5, MOSI=P0_6.
Started reading 30717 bytes from SPI FLASH offset 0x0.
SPI FLASH memory reading has finished. Read 30717 bytes.
******************************************