Legacy-Free Keyboard/Embedded Controller with SPI and LPC Docking Interface
Chapter 13 Keyboard Controller
13.1
8042 Style Host Interface
The LPC47N350 keyboard controller uses a High-Performance 8051 microcontroller CPU core to
produce a superset of the features provided by the industry-standard 8042 keyboard controller. Added
features include two high-drive serial interfaces, and additional interrupt sources. The LPC47N350
provides an industry standard 8042-style LPC host interface to the High-Performance 8051 to emulate
standard 8042 keyboard controller and preserve software backward compatibility with the system BIOS.
The LPC47N350’s LPC keyboard interface is functionally compatible with the 8042-style host interface.
The keyboard controller has the KBD (Keyboard) Status register, KBD Data/Command Write register,
and KBD Data Read register.
Table 13.1 shows how the has the LPC interface accesses the keyboard controller. In addition to the
above signals, the host interface includes keyboard and mouse interrupts.
13.2
Keyboard Controller Register Description
Table 13.1 Keyboard Controller LPC I/O Address Map
HOST ADDRESS
COMMAND
FUNCTION
Keyboard Data Write (C/D=0)
0x60
Write
Read
Write
Read
Keyboard Data Read
0x64
Keyboard Command Write (C/D=1)
Keyboard Status Read
Note: These registers consist of three separate 8 bit registers: KBD Status, KBD Data/Command
Write and KBD Data Read.
13.2.1 Keyboard Data Write
This is an 8 bit write only register. When written, the C/D status bit of the status register is cleared to
zero and the IBF bit is set.
13.2.2 Keyboard Data Read
This is an 8 bit read only register. When read, the PBOBF and/or AUXOBF interrupts are cleared and
the OBF flag in the status register is cleared.
13.2.3 Keyboard Command Write
This is an 8 bit write only register. When written, the C/D status bit of the status register is set to one
and the IBF bit is set.
13.2.4 Keyboard Status Read
This is an 8 bit read only register. Refer to the description of the Status Register (7FF2H) for more
information.
SMSC LPC47N350
143
Revision 1.1 (01-14-03)
DATASHEET
SMSC [ SMSC CORPORATION ]
