Protocol 7.00 packet format#

All packets with Protocol 7.00 have the following header:

Size

Field name

Description

Values

1 B

Type (T)

Basic purpose of the packet

0x00 to 0x1F

2 B

Subtype (ST)

Specific function of the packet

2-chars ASCII-HEX value, 00 to FF

1 B

Extended (EX)

Whether data is attached to the packet

1-char ASCII-HEX value, 0 or 1

If the packet is extended, i.e. if EX is set to 1, the following extension is appended to the header:

Size

Field name

Description

Values

4 B

Data size (DS)

Size of the D field

4-char ASCII-HEX value, 0000 to FFFF

DS B

Data (D)

Additional data

0x5C padding encoded data

All packets have the following footer:

Size

Field name

Description

Values

2 B

Checksum (CS)

Checksum for integrity check

2-char ASCII-HEX value, 00 to FF

The checksum can be obtained or verified by summing all bytes going from ST to D if present, or EX if not, and adding 1 to its bitwise complement.

The interpretation of the packet depends on the value of T. See the following sections for more information.

0x01 – Command packet#

The command packet reflects an order given by the active side to the passive side. The packet subtype (ST) contains the command code.

If the packet is extended, the packet data (D) is usually formatted the following way:

Offset

Size

Field name

Description

Values

0 (0x00)

2 B

Overwrite (OW)

Mode of operation if a file exists.

2-char ASCII-HEX value:

  • 00: Request user confirmation.

  • 01: Terminate if exists.

  • 02: Force overwrite.

2 (0x02)

2 B

Data type (DT)

Data type.

2-char ASCII-HEX value, 00.

4 (0x04)

8 B

File size (FS)

Size of the file being transferred.

8-char ASCII-HEX value.

12 (0x0C)

2 B

Data size 1 (SD1)

Size of D1

2-char ASCII-HEX value.

14 (0x0E)

2 B

Data size 2 (SD2)

Size of D2

2-char ASCII-HEX value.

16 (0x10)

2 B

Data size 3 (SD3)

Size of D3

2-char ASCII-HEX value.

18 (0x12)

2 B

Data size 4 (SD4)

Size of D4

2-char ASCII-HEX value.

20 (0x14)

2 B

Data size 5 (SD5)

Size of D5

2-char ASCII-HEX value.

22 (0x16)

2 B

Data size 6 (SD6)

Size of D6

2-char ASCII-HEX value.

24 (0x16)

SD1 B

Data 1 (D1)

First argument

24 (0x16) + SD1

SD2 B

Data 2 (D2)

Second argument

24 (0x16) + SD1 + SD2

SD3 B

Data 3 (D3)

Third argument

24 (0x16) + SD1 + SD2 + SD3

SD4 B

Data 4 (D4)

Fourth argument

24 (0x16) + SD1 + SD2 + SD3 + SD4

SD5 B

Data 5 (D5)

Fifth argument

24 (0x16) + SD1 + SD2 + SD3 + SD4 + SD5

SD6 B

Data 6 (D6)

Sixth argument

Warning

There is an exception, i.e. a command that uses a different payload format: command 56 “Upload and run”.

0x02 – Data packet#

The data packet is used to transfer “raw” data, as described in Transferring data.

The packet subtype (ST) must be the same as the subtype (ST) of the command that has initiated the data transmission; e.g. if the data flow has been initiated following command 25 “Transfer file” (main memory), all data packets in the corresponding flow must bear the ST 25.

All data packets are expected to be extended (i.e. EX is set to 1). The layout of D is the following:

Size

Field name

Description

Values

4 B

Total number (TN)

Total number of data packets in current transmission

4-char ASCII-HEX value, 0001 to FFFF.

4 B

Current number (CN)

Current data packet number in current transmission

4-char ASCII-HEX value, 0001 to FFFF.

0-512 B

Contents (DD)

Contents of data packet

Note that since 512 bytes is the maximum transmittable amount, and that 0x5C padding can only double the data size, the maximum size of transmitted data within one data packet is 256 bytes.

0x03 – Roleswap packet#

The roleswap packet indicates a roleswap, and is used for transfer requests; see Requesting data transfer(s) for more information.

Such packets will never be extended, and will never have another subtype than 00.

0x05 – Check packet#

This covers two different packet types, depending on the subtype (ST):

  • If ST is 00, this is an initial check packet used to establish communication with the calculator. See Initiating the link for more information.

  • If ST is 01, this is a regular check packet used to check if the link is still up with the calculator. See Checking up on the link for more information.

This packet is not expected to be extended, i.e. EX should be 0.

0x06 – Acknowledgement (ACK) packet#

This covers two different packet types, depending on the subtype (ST):

  • If ST is 00, this is a basic acknowledgement whose role can be interpreted differently depending on the flow. It is not expected to be extended, i.e. EX should be 0.

  • If ST is 01, this is an overwrite confirmation; see Confirming or rejecting overwrite for more details on the related flow.

  • If ST is 02, this is an extended acknowledgement (EACK), providing additional information, i.e. the packet is extended and EX should be set to 1.

    This is only used in the flow to get device information; see Requesting device information and 01 “Get device information” for more information.

  • If ST is 03, this means the acknowledge packet also marks the end of the communication.

The payload for an extended acknowledgement is the following:

If ST is set to 02, the packet data (D) is expected to be 164 (0xA4) bytes long, and structured the following way:

If ST is set to 02, the packet data (D) is expected to be one of:

  • 164 (0xA4) bytes long for fx-9860G and compatible models.

  • 188 (0xBC) bytes long for the fx-CG family of models.

The format of the 164 bytes long payload is the following:

Offset

Size

Field name

Description

Values

0 (0x00)

8 B

Hardware Identifier (HWID)

Hardware identifier for the calculator.

See Known hardware identifiers for Protocol 7.00 for known hardware identifiers.

8 (0x08)

16 B

Processor Identifier (CPUID)

String describing the processor used by the calculator. Is known to be incorrect, it is recommended not to use this field.

RENESAS SH735501

24 (0x18)

8 B

Preprogrammed ROM capacity

Capacity of the preprogrammed ROM, in KB

8-char ASCII-DEC value, e.g. 00000000.

32 (0x20)

8 B

Flash ROM capacity

Capacity of the flash ROM, in KB

8-char ASCII-DEC value, e.g. 00004096.

40 (0x28)

8 B

RAM capacity

Capacity of the RAM, in KB

8-char ASCII-DEC value, e.g. 00000512.

48 (0x30)

16 B

Preprogrammed ROM version

Version of the preprogrammed ROM, as an OS version

xx.xx.xxxx + \xFF\xFF\xFF\xFF\xFF\xFF

64 (0x40)

16 B

Boot code version

Version of the bootcode, as an OS version

xx.xx.xxxx + \xFF\xFF\xFF\xFF\xFF\xFF

80 (0x50)

8 B

Boot code offset

Offset of the boot code on the ROM, as a 32-bit address.

8-char ASCII-HEX value.

88 (0x58)

8 B

Boot code size

Size of the boot code, in KB.

8-char ASCII-HEX value.

96 (0x60)

16 B

OS code version

Version of the OS, as an OS version

xx.xx.xxxx + \xFF\xFF\xFF\xFF\xFF\xFF

112 (0x70)

8 B

OS code offset

Offset of the OS on the ROM, as a 32-bit address.

8-char ASCII-HEX value.

120 (0x78)

8 B

OS code size

Size of the OS on the ROM, in KB.

8-char ASCII-HEX value.

128 (0x80)

4 B

Protocol version

Version of the protocol in use.

7.00

132 (0x84)

16 B

Product Identifier

Identifier of the calculator.

8-char alphabetical (upper and lower case) identifier.

148 (0x94)

16 B

User Name

Name set by the user in SYSTEM

The format of the 164 bytes long payload is the following:

Offset

Size

Field name

Description

Values

0 (0x00)

148 B

…

Equivalent to the 164 bytes long payload up to the Product Identifier, included.

See above.

148 (0x94)

20 B

User Name

Set by the user in SYSTEM.

168 (0xA8)

20 B

Organisation Name

Set by the user in SYSTEM.

0x15 – Negative acknowledgement (NAK) packet#

This covers multiple packet types, depending on the subtype (ST):

  • If ST is 00, a default error is returned.

  • If ST is 01, the previously received packet is invalid and requires resending from the other side. See Reporting invalid checksums for more information on the usage of this error.

  • If ST is 02, the operation requires an overwrite confirmation; see Confirming or rejecting overwrite for more details on the related flow.

  • If ST is 03, the active side is signalling an overwrite rejection from the user to the passive side; see Confirming or rejecting overwrite for more details on the related flow.

  • If ST is 04, the error is a generic error that terminates the link.

  • If ST is 05, the memory is full and the link is also terminated.

0x18 – Terminate packet#

This data packet is used by the active side to signal termination of the link usage. The subtype (ST) represents the reason for termination:

  • ST being set to 00 is the default case.

  • If ST is set to 01, it means that the user has requested termination from either the active or passive side.

  • If ST is set to 02, it means that the termination is due to timeouts, likely due to checking flows having failed; see Checking up on the link for more information.

  • If ST is set to 03, it means that the termination is due to an overwrite request having been denied by the user on the active side.

All termination packets should not be extended, i.e. EX should be 0.

See Terminating the link for more information on the link termination flow.