ALFAT-OM-337 GHI Electronics, ALFAT-OM-337 Datasheet - Page 29

• Manufacturer Part Number: ALFAT-OM-337
• Description: Memory IC Development Tools ALFAT USB / SD to UART / SPI OEM BOARD
• Manufacturer: GHI Electronics

Specifications of ALFAT-OM-337

• Rohs: yes
• Product: SD OEM Board
• Tool Is For Evaluation Of: SD, SDHC, MMC Cards, USB drives
• Memory Type: Flash
• Operating Supply Voltage: 3.3 V
• Description/function: OEM board offers a seamless way to access files on SD & MMC cards and on USB memory drives
• Interface Type: I2C, SPI, UART, USB
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Part # Aliases: GHI-ALFAT-OM-337

GHI Electronics
Rev. 1.13
W - Write to File
L- Fast Write to File (SPI mode only)
This command is called to write data through a file handle assigned to an open file with
write or append mode:
The sent data is written directly to the file as is (no interpretation or conversion). Also,
the user should make sure that the sent data size matches the size declared in the
command. If an error occurs while writing, ALFAT still expects all the data then it sends
back the error code.
There is no line-feed sent after the data. If writing “Hello” to a file, just send the 5 bytes
and then ALFAT will respond with how many bytes were written. In this case, it should
be $00000005.
To make sure that the data is written to a file, the file must be flushed (F command) or
closed (C command) when done, or there will be a risk of losing data or corrupting the
file system if the storage media was removed or if there was a power loss.
This command is called to write data through a file handle assigned to an open file with
write or append mode. IT the utilization of this command is similar to Command's but it
works only through SPI interface and it uses the help of an internal DMA to gain much
higher data SPI receive rate (Average 1.4 MByte per second) than with the regular W
command. For more details about data throughput check
Overhead.
Format
Example W
1. Send W command with file handle and the data size.
2. Wait till you get the acknowledge.
3. Send the data.
W
!00
User sends data
(ssssssss bytes)
$aaaaaaaa
!00
!00
1234567890abcdef
$00000010
!00<LF>
<SP>
<SP>
<LF>
<LF>
<LF>
n>ssssssss
1>10
<LF>
<LF>
<LF>
<LF>
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n File Handle 0, 1, 2,3,4,5,6, 7, 8, 9, A, B,
C, D, E or F.
ssssssss 4 bytes Max. in HEX data size
to be written
aaaaaaaa 4 bytes always in HEX actual
written size
Write 16 bytes to the file associated with
handle 1
Serial Interface Speed
ALFAT SoC Processor
ALFAT Command Set
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