RTL8100C & RTL8100CL
Datasheet
RID: Revision ID Register
The Revision ID register is an 8-bit register that specifies the RTL8100C(L) controller revision number.
PIFR: Programming Interface Register
The programming interface register is an 8-bit register that identifies the programming interface of the
RTL8100C(L) controller.
PIFR = 00h (the PCI version 2.1 specification does not define any specific value for network devices).
SCR: Sub-Class Register
The Sub-class register is an 8-bit register that identifies the function of the RTL8100C(L).
SCR = 00h indicates that the RTL8100C(L) is an Ethernet controller.
BCR: Base-Class Register
The Base-Class Register is an 8-bit register that broadly classifies the function of the RTL8100C(L).
BCR = 02h indicates that the RTL8100C(L) is a network controller.
CLS: Cache Line Size
Reads will return a 0, writes are ignored.
LTR: Latency Timer Register
Specifies, in units of PCI bus clocks, the value of the latency timer of the RTL8100C(L).
When the RTL8100C(L) asserts FRAMEB, its latency timer starts to count. If the RTL8100C(L) deasserts
FRAMEB prior to count expiration, the contents of the latency timer are ignored. Otherwise, after the count
expires, the RTL8100C(L) initiates transaction termination as soon as its GNTB is deasserted. Software is able
to read or write, and the default value is 00H.
HTR: Header Type Register
Reads will return a 0, writes are ignored.
BIST: Built-In Self Test
Reads will return a 0, writes are ignored.
IOAR: Input Output Address Register
This register specifies the base IO address that is required to build an address map during configuration. It
also specifies the number of bytes required as well as an indication that it can be mapped into IO space.
Table 43. Base IO Address
Bit
31-8 IOAR31-8 Base IO Address.
This is set by software to the base IO address for the operational register map.
IO Size.
Symbol
Description
7-2
IOSIZE
Read back as 0. This allows the PCI bridge to determine that the RTL8100C(L) requires 256 bytes of
IO space.
1
0
-
Reserved.
IO Space Indicator.
IOIN
Read only. Set to 1 by the RTL8100C(L) to indicate that it is capable of being mapped into IO space.
Single-Chip Fast Ethernet Controller
42
Track ID: JATR-1076-21 Rev. 1.06