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   232R/245R        channel_a_type   0
  13 00.1    |      0       0   channel_a_type                    channel_a_type   0
  14 00.2    |      0       0   channel_a_type   high_current     channel_a_type   0
  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    channel_c_driver
  20
  21 On TYPE_R 00.0 is set for the FT245R and cleared for the FT232R
  22 On TYPE_R 00.3 set mean D2XX, on other devices VCP
  23
  24 01.0    |      0       0   channel_b_type                    channel_b_type   0
  25 01.1    |      0       0   channel_b_type                    channel_b_type   0
  26 01.2    |      0       0   channel_b_type   0                channel_b_type   0
  27 01.3    |      0       0   channel_b_driver 0                channel_b_driver channel_b_driver
  28 01.4    |      0       0   high_current_b   0                0                0
  29 01.5    |      0       0   0                0                0                0
  30 01.6    |      0       0   0                                 0                0
  31 01.7    |      0       0   0                0                0                channel_d_driver
  32
  33 Fixme: Missing 4232H validation
  34
  35 02     | Vendor ID (VID) LSB (all)
  36 03     | Vendor ID (VID) MSB (all)
  37 04     | Product ID (PID) LSB (all)
  38 05     | Product ID (PID) MSB (all)
  39 06     | Device release number LSB (not tested on TYPE_4232H)
  40 07     | Device release number MSB (not tested on TYPE_4232H)
  41        |
  42 08.4   | Battery powered
  43 08.5   | Remote wakeup
  44 08.6   | Self powered: 1, bus powered: 0
  45 08.7   | Always 1
  46        |
  47 09     | Max power (mA/2)
  48        |
  49 Byte.BIT| TYPE_AM TYPE_BM            TYPE_2232C         TYPE_R       TYPE_2232H        TYPE_4232H
  50 0a.0    | 0       IsoIn              IsoIn part A       0            0                 0
  51 0a.1    | 0       IsoOut             IsoOut part A      0            0                 0
  52 0a.2    | 0       suspend_pull_down  suspend_pull_down               suspend_pull_down suspend_pull_down
  53 0a.3    | 0       use_serial                                         use_serial        use_serial
  54 0a.4    | 0       change_usb_version change_usb_version
  55 0a.5    | 0       0                  IsoIn part B       0            0                 0
  56 0a.6    | 0       0                  IsoOut part B      0            0                 0
  57 0a.7    | 0 - reserved
  58
  59 0b      | TYPE_R Bitmask Invert, 0 else
  60 Byte.BIT| TYPE_4232H
  61 0b.4    | channel_a_rs485enable
  62 0b.5    | channel_b_rs485enable
  63 0b.6    | channel_c_rs485enable
  64 0b.7    | channel_d_rs485enable
  65
  66 Byte   | TYPE_AM TYPE_BM     TYPE_2232C   TYPE_R       TYPE_2232H       TYPE_4232H
  67 0c     | 0       USB-VER-LSB USB-VER-LSB  0            ?                ?
  68 0d     | 0       USB-VER-MSB USB-VER-MSB  0            ?                ?
  69 (On several FT2232H different values were observed -> The value is unused
  70  if change USB version is not set, so it might contain garbage)
  71
  72 0e     | OFFSET Vendor
  73 0f     | Len    VENDOR
  74
  75 10     | Offset Product
  76 11     | Length Product
  77
  78 12     | Offset Serial
  79 13     | Length Serial
  80
  81 Byte.BIT| TYPE_AM TYPE_BM   TYPE_2232C   TYPE_R       TYPE_2232H       TYPE_4232H
  82 14.3:0  | UA      UA        CHIP         CBUS[0]      AL               A
  83 14.7:0  | UA      UA        CHIP         CBUS[1]      AH               B
  84 15.3:0  | UA      UA        0            CBUS[2]      BL               C
  85 15.7:0  | UA      UA        0            CBUS[3]      BH               D
  86 16.3:0  | UA      UA        UA           CBUS[4]      0                0
  87 16.7:0  | UA      UA        UA           0            0                0
  88
  89 CHIP values:
  90 0x46: EEPROM is a 93xx46
  91 0x56: EEPROM is a 93xx56
  92 0x66: EEPROM is a 93xx66
  93
  94 17        UA      UA        UA           0            0                0
  95 18        UA      UA        UA           VENDOR       CHIP             CHIP
  96 19        UA      UA        UA           VENDOR       0                0
  97
  98 1a        UA (all)
  99
 100
 101 Additional fields after the serial string:
 102 0x00, 0x00 - reserved for "legacy port name prefix"
 103 0x00, 0x00 - reserved for plug and play options
 104 (Observed values with PnP == 0:
 105 0x02 0x03 0x01 0x00)
 106
 107 Note: The additional fields after the serial number string
 108 collide with the official FTDI formula from AN_121 regarding
 109 the start of the user area:
 110 "Start Address = the address following the last byte of SerialNumber string."