RTFM знает XMega A Manual Rev.H p.216:
19.7 Enabling External Driver Interface
An external drivers interface can be enabled. When this is done the internal TWI drivers with
input filtering and slew rate control are bypassed. The normal I/O pin function is used and the
direction must be configured by the user software. When this mode is enabled an external TWI
compliant tri-state driver is needed for connecting to a TWI bus.
By default port pin 0 (Pn0) and 1 (Pn1) is used for SDA and SCL. The external driver interface
uses port pin 0 to 3 for the signals SDA_IN, SCL_IN, SDA_OUT and SCL_OUT.
MBedder, терминатор (19.02.2012 13:13 - 13:20, просмотров: 114) ответил Idler на У XMEGA_A1/A3 заявлен режим работы TWI(I2C) с внешним буфером, через SCLOUT, SDAOUT, SCLIN, SDAIN. И бит, включающий этот режим есть. Но в таблице функций ног только SCL/SDA. Куда цеплять SCLIN/SDAIN? Кто-нибудь знает?