
SMSC LPC47B27x
- 19 -
Rev. 08-10-04
DATASHEET
FUNCTIONAL DESCRIPTION
SUPER I/O REGISTERS
The address map, shown below in Table 1, shows the addresses of the different blocks of the Super I/O immediately
after power up. The base addresses of the FDC, serial and parallel ports, PME register block, Game port and
configuration register block can be moved via the configuration registers. Some addresses are used to access more
than one register.
HOST PROCESSOR INTERFACE (LPC)
The host processor communicates with the LPC47B27x through a series of read/write registers via the LPC interface.
The port addresses for these registers are shown in Table 1. Register access is accomplished through I/O cycles or
DMA transfers. All registers are 8 bits wide.
Table 1 - Super I/O Block Addresses
ADDRESS
BLOCK NAME
Base+(0-5) and +(7)
Floppy Disk
Base+(0-7)
Serial Port Com 1
Base1+(0-7)
Base2+(0-7)
Base+(0-3)
Base+(0-7)
Base+(0-3), +(400-402)
Base+(0-7), +(400-402)
ECP+EPP+SPP
60, 64
KYBD
Base + 0
Game Port
Base + (0-5F)
Runtime Registers
Base + (0-1)
MPU-401
Base + (0-1)
Configuration
Note 1: Refer to the configuration register descriptions for setting the base address.
LPC INTERFACE
The following sub-sections specify the implementation of the LPC bus.
LPC Interface Signal Definition
The signals required for the LPC bus interface are described in the table below. LPC bus signals use PCI 33MHz
electrical signal characteristics.
SIGNAL NAME
TYPE
LAD[3:0]
I/O
LPC address/data bus. Multiplexed command, address and data bus.
nLFRAME
Input
Frame signal. Indicates start of new cycle and termination of broken
cycle
nPCI_RESET
Input
PCI Reset. Used as LPC Interface Reset.
nLDRQ
Output
Encoded DMA/Bus Master request for the LPC interface.
nIO_PME
OD
Power Mgt Event signal. Allows the LPC47B27x to request wakeup.
nLPCPD
Input
Powerdown Signal. Indicates that the LPC47B27x should prepare for
power to be shut on the LPC interface.
SER_IRQ
I/O
Serial IRQ.
PCI_CLK
Input
PCI Clock.
Note: The nCLKRUN signal is not implemented in this part.
LOGICAL
DEVICE
0
4
5
NOTES
IR Support
Consumer IR
Serial Port Com 2
Parallel Port
SPP
EPP
ECP
3
7
9
A
B
DESCRIPTION