Legacy-Free Keyboard/Embedded Controller with SPI and LPC Docking Interface
Note: Bits D0 and D2 in the ECI Primary Base Address Low Byte must be “0”. For example, 0x62 is
a valid ECI Base Address, while 0x66 is not a valid ECI Base Address. The valid ECI Primary
Base Address range is 0x0000 – 0x0FFA.
Table 4.1 ECI Configuration Registers (LDN8)
VCC1 &
HARD
SOFT
VCC2
POR
VCC0
POR
INDEX TYPE RESET
RESET
DESCRIPTION
D7 D6 D5 D4 D3 D2
D1
D0
0x30
0x60
0x61
R/W
R/W
R/W
0x00
0x00
0x62
0x00
0x00
0x62
0x00
0x00
0x62
-
-
-
ACTIVATE
Reserved
Activate
ECI PRIMARY BASE ADDRESS HIGH BYTE
“0” “0” “0” “0” A11 A10 A9
A8
ECI PRIMARY BASE ADDRESS LOW BYTE (See
Note 4.1))
A7 A6 A5 A4
A3
“0”
A1
“0”
Note 4.1 Bits D0 and D2 of the ECI Base Address Low Byte must be “0”.
4.2
ECI Runtime Registers
An ACPI-compliant ECI contains three registers: EC_COMMAND, EC_STATUS, and EC_DATA. The
ECI registers occupy two addresses in the Host I/O space (Table 4.2).
The EC_DATA and EC_COMMAND registers appear as a single 8-bit data register in the 8051. The
CMD bit in the EC_STATUS register is used by the 8051 to discriminate commands from data written
by the host to the ECI. CMD is controlled by hardware: host writes to the EC_DATA register set CMD
= “0”; host writes to the EC_COMMAND register set CMD = “1”.
Descriptions of these registers follow in the sections below.
Table 4.2 ECI Run-Time Registers
ISA HOST INTERFACE
8051 INTERFACE
CMD
8051
REGISTER
HOST
(Note
4.2)
INDEX
8051
POWER
PLANE
VCC1
POR
VCC2
POR
NAME
HOST INDEX
TYPE
(7F00+) TYPE
EC_DATA
ECI Base Address
R/W
W
0
1
-
0x53
0x53
0x54
R/W
R
VCC1
-
-
-
-
-
EC_COMMAND
EC_STATUS
ECI Base Address + 4
R
R/W
0x00
Note 4.2 CMD is bit D3 in the EC_STATUS register.
4.3
EC_STATUS Register
The EC_STATUS register indicates the state of the Embedded Controller Interface. To the host, the
EC_STATUS register is read-only. To the 8051, some bits in the EC_STATUS register are read-only
(Table 4.3). These bits are controlled by hardware. The 8051 software controlled bits in the
EC_STATUS register are read/write.
Revision 1.1 (01-14-03)
SMSC LPC47N350
DATA2S2HEET
SMSC [ SMSC CORPORATION ]
