developer.intra2net.com Git - libftdi/blob - doc/EEPROM-structure

   1 Here we try to document what we know about the EEPROM Structure.
   2
   3 Even with a 93xx66 EEPROM, at maximum 256 Bytes are used
   4
   5 All important things happen in the first
   6 0x14(FT232/245), 0x16(FT2232CD), 0x18(FT232/245R) or 0x1a (FT2232H/4432H) bytes
   7
   8 Type   |  Use extra EEPROM space
   9 FT2XXB |  No
  10
  11 Byte.BIT| TYPE_AM TYPE_BM   TYPE_2232C       TYPE_R          TYPE_2232H       TYPE_4232H
  12 00.0    |      0       0   channel_a_type                    channel_a_type   channel_a_type
  13 00.1    |      0       0   channel_a_type                    channel_a_type   channel_a_type
  14 00.2    |      0       0   channel_a_type   high_current     channel_a_type   channel_a_type
  15 00.3    |      0       0   channel_a_driver channel_a_driver channel_a_driver channel_a_driver
  16 00.4    |      0       0   high_current_a   0                0                0
  17 00.5    |      0       0   0                0                0                0
  18 00.6    |      0       0   0                0                0                0
  19 00.7    |      0       0   0                0                SUSPEND_DBUS7    0
  20
  21 On TYPE_R 00.3 set mean D2XX, on other devices VCP
  22
  23 01.0    |      0       0   channel_b_type                    channel_b_type   channel_b_type
  24 01.1    |      0       0   channel_b_type                    channel_b_type   channel_b_type
  25 01.2    |      0       0   channel_b_type   0                channel_b_type   channel_b_type
  26 01.3    |      0       0   channel_b_driver 0                channel_b_driver channel_b_driver
  27 01.4    |      0       0   high_current_b   0                0                0
  28 01.5    |      0       0   0                0                0                0
  29 01.6    |      0       0   0                                 0                0
  30 01.7    |      0       0   0                0                0                0
  31
  32 Fixme: Missing 4232H validation and channel_c_driver, channel_d_driver, channel_a|b|c|d_rs484enable
  33
  34 02     | Vendor ID (VID) LSB (all)
  35 03     | Vendor ID (VID) MSB (all)
  36 04     | Product ID (PID) LSB (all)
  37 05     | Product ID (PID) MSB (all)
  38 06     | Device release number LSB (not tested on TYPE_4232H)
  39 07     | Device release number MSB (not tested on TYPE_4232H)
  40        |
  41 08.4   | Battery powered
  42 08.5   | Remote wakeup
  43 08.6   | Self powered: 1, bus powered: 0
  44 08.7   | Always 1
  45        |
  46 09     | Max power (mA/2)
  47        |
  48 Byte.BIT| TYPE_AM TYPE_BM            TYPE_2232C        TYPE_R       TYPE_2232H       TYPE_4232H
  49 0a.0    | 0       IsoIn              IsoIn part A      0            0                0
  50 0a.1    | 0       IsoOut             IsoOut part A     0            0                0
  51 0a.2    | 0       suspend_pull_down suspend_pull_down               suspend_pull_down
  52 0a.3    | 0       use_serial                                        use_serial
  53 0a.4    | 0       change_usb_version change_usb_version
  54 0a.5    | 0       0                  IsoIn part B      0            0                0
  55 0a.6    | 0       0                  IsoOut part B     0            0                0
  56 0a.7    | 0 - reserved
  57
  58        |
  59 0b     | TYPE_R Bitmask Invert, 0 else
  60
  61 Byte   | TYPE_AM TYPE_BM     TYPE_2232C   TYPE_R       TYPE_2232H       TYPE_4232H
  62 0c     | 0       USB-VER-LSB USB-VER-LSB  0            ?                ?
  63 0d     | 0       USB-VER-MSB USB-VER-MSB  0            ?                ?
  64 (On several FT2232H different values were observed -> The value is unused
  65  if change USB version is not set, so it might contain garbage)
  66
  67 0e     | OFFSET Vendor
  68 0f     | Len    VENDOR
  69
  70 10     | Offset Product
  71 11     | Length Product
  72
  73 12     | Offset Serial
  74 13     | Length Serial
  75
  76 Byte.BIT| TYPE_AM TYPE_BM   TYPE_2232C   TYPE_R       TYPE_2232H       TYPE_4232H
  77 14.3:0  | UA      UA        CHIP         CBUS[0]      AL               A
  78 14.7:0  | UA      UA        CHIP         CBUS[1]      AH               B
  79 15.3:0  | UA      UA        0            CBUS[2]      BL               C
  80 15.7:0  | UA      UA        0            CBUS[3]      BH               D
  81 16.3:0  | UA      UA        UA           CBUS[4]      0                0
  82 16.7:0  | UA      UA        UA           0            0                0
  83
  84 CHIP values:
  85 0x46: EEPROM is a 93xx46
  86 0x56: EEPROM is a 93xx56
  87 0x66: EEPROM is a 93xx66
  88
  89 17        UA      UA        UA           0            0                0
  90 18        UA      UA        UA           VENDOR       CHIP             CHIP
  91 19        UA      UA        UA           VENDOR       0                0
  92
  93 1a        UA (all)
  94
  95
  96 Additional fields after the serial string:
  97 0x00, 0x00 - reserved for "legacy port name prefix"
  98 0x00, 0x00 - reserved for plug and play options
  99 (Observed values with PnP == 0:
 100 0x02 0x03 0x01 0x00)
 101
 102 Note: The additional fields after the serial number string
 103 collide with the official FTDI formula from AN_121 regarding
 104 the start of the user area:
 105 "Start Address = the address following the last byte of SerialNumber string."