ALFAT-OM-337 GHI Electronics, ALFAT-OM-337 Datasheet - Page 15

• 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
Read Transaction
Response Frame
RFB is Ready Flag Byte.
When a write transaction request is being sent, ALFAT returns zero with the first
received byte (Frame Type) and then it returns a ready flag with the received second
byte (Size LSB).
If the ready flag is 0x00, this means that ALFAT is not ready to receive any data over
SPI. The current transaction gets terminated and the user must not send more bytes for
this frame.
If the ready flag is 0x01, this means that ALFAT is ready to receive and the user can
proceed and send Size MSB and the payload bytes.
Processing read transaction is preformed by sending read request frames and receiving
response frames that carry the useful payload.
Request Frame
The frame consists of two parts, a header and stuffing bytes.
Response Frame
The frame consists of two parts, a header and payload.
•
•
•
•
Frame
Frame
Ignore
Type
Type
0x01
0x02
The header consists of three bytes. The first byte is the frame type, the second
and the third bytes are the requested 16-bit transaction length.
Stuffing bytes: the bytes should always be 0x00. This section size should equal
P, where P is the actual payload size that ALFAT will send back.
The header consists of three bytes. The first byte is ignored, the second and the
third bytes are 16-bit value ACT that indicates the actual data size available in
the send buffer of ALFAT. ACT value could be more or less that N (the requested
transaction size)
Payload: This is the actual transaction payload that is being send out from ALFAT
to the host. This section size is P.
Size LSB Size MSB
16-bit Transaction
N LSB
RFB
16-bit Size N
Transaction
Requested
Size N
N MSB
RFB
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Byte 1
0x00
RFB
Stuffing Bytea, the size is P.
Byte 2
0x00
RFB
Payload
ALFAT access interface
0x00
ALFAT SoC Processor
...
...
www.ghielectronics.com
Byte N
0x00
RFB