LPC47N237-MD SMSC [SMSC Corporation], LPC47N237-MD Datasheet - Page 91

• Manufacturer Part Number: LPC47N237-MD
• Description: 3.3V I/O CONTROLLER FOR PORT REPLICATORS AND DOCKING STATIONS
• Manufacturer: SMSC [SMSC Corporation]

3.3v I/O Controller for Port Replicators and Docking Stations
Chapter 17 Configuration
17.1
Note 17.1
Note 17.2
17.2
17.2.1 Entering the Configuration State
SMSC DS – LPC47N237
CONFIG PORT
INDEX PORT
DATA PORT
The configuration of the LPC47N237 is programmed through hardware selectable Configuration Access
Ports that appear when the chip is placed into the configuration state. The LPC47N237 logical device
blocks, if enabled, will operate normally in the configuration state.
Configuration Access Ports
The Configuration Access Ports are the CONFIG PORT, the INDEX PORT, and the DATA PORT (Table
17.1).
Configuration Port Base Address registers CR12 and CR13. To determine the configuration base address
at power-up, the state of the LGP47 (SYSOPT) pin is latched by the falling edge of a hardware reset. If
the latched state is a 0, the base address of the Configuration Access Ports is located at address 0x02E; if
the latched state is a 1, the base address is located at address 0x04E. The base address is relocatable
via CR12 and CR13.
Configuration State
The configuration registers are used to select programmable chip options. The LPC47N237 operates in
two possible states: the run state and the configuration state. After power up by default the chip is in the
run state. To program the configuration registers, the configuration state must be explicitly enabled.
Programming the configuration registers typically follows this sequence:
1.
2.
3.
To enter the configuration state write the Configuration Access Key to the CONFIG PORT.
Configuration Access Key is one byte of 55H data.
Configuration Access Ports following this procedure.
The INDEX and DATA ports are active only when the LPC47N237 is in the configuration state.
The INDEX PORT is only readable in the configuration state.
PORT NAME
Enter the Configuration State,
Program the Configuration Register(s),
Exit the Configuration State.
The base address of these registers is controlled by the LGP47 (SYSOPT) pin and by the
Table 17.1 – Configuration Access Ports
SYSOPT = 0
DATASHEET
0x02E
0x02E
INDEX PORT + 1
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The LPC47N237 will automatically activate the
SYSOPT = 1
0x04E
0x04E
(Note 17.1, Note
17.2)
READ/WRITE
(Note 17.1)
WRITE
READ/WRITE
TYPE
Revision 0.3 (10-26-04)
The