SNC(4) (i386)
SNC(4) FreeBSD Kernel Interfaces Manual (i386) SNC(4)


sncNational Semiconductor DP8393X SONIC Ethernet adapter driver


device isa
device snc


The snc driver provides support for the National Semiconductor SONIC Ethernet adapters.


The snc driver supports the following cards:

  • National Semiconductor DP83934AVQB
  • NEC PC-9801-83
  • NEC PC-9801-84
  • NEC PC-9801-103
  • NEC PC-9801-104
  • NEC PC-9801N-15
  • NEC PC-9801N-25
  • NEC PC-9801N-J02 PCMCIA
  • NEC PC-9801N-J02R PCMCIA

The snc driver also includes support for the National Semiconductor NS46C46 as 64 * 16 bits Microwave Serial EEPROM.


Accessing SONIC card data structures and registers as 32 bit values makes code endianness independent. The SONIC is however always in big-endian mode so it is necessary to ensure that data structures shared between the CPU and the SONIC card are always in big-endian order. The snc driver supports the PC-98 C-Bus, and PnP buses. Support is also provided for the legacy C-Bus.


The following driver specific error messages may be reported:
snc%d: snc_nec16_register_irq: unsupported irq (%d)
The card returned an IRQ which is not supported by the driver.
snc%d: invalid packet length %d bytes
An attempt to transfer a data packet failed due to an invalid packet length.


The snc driver was ported from NetBSD by Motomichi Matsuzaki <mzaki@e-mail.ne.jp> and Hiroshi Yamashita <bluemoon@msj.biglobe.ne.jp>. It first appeared in FreeBSD 4.2. This manual page first appeared in FreeBSD 5.3.


This manual page was written by Tom Rhodes <trhodes@FreeBSD.org>.


Currently the snc driver only works on the PC-98 architecture. It should probably work on the i386 architecture as well.
September 4, 2004 FreeBSD