LPC47N227TQFP Standard Microsystems (SMSC), LPC47N227TQFP Datasheet - Page 112

• Manufacturer Part Number: LPC47N227TQFP
• Manufacturer: Standard Microsystems (SMSC)

Specifications of LPC47N227TQFP

• Lead Free Status / RoHS Status: Not Compliant

FDD Interface Pins
All pins in the FDD interface which can be connected directly to the floppy disk drive itself are either
DISABLED or TRISTATED.
Pins used for local logic control or part programming are unaffected. Table 46 depicts the state of the
floppy disk drive interface pins in the powerdown state.
UART Power Management
Direct power management is controlled by CR02. Refer to the Configuration section for more information.
Auto Power Management is enabled by the UART1 and UART2 enable bits in CR07. When set, these
bits allow the following auto power management operations:
1.
2.
Note:
Exit Auto Powerdown
The transmitter exits powerdown on a write to the XMIT buffer. The receiver exits auto powerdown when
RXDx changes state.
Parallel Port
Direct power management is controlled by Bit[2] in CR01. Refer to the Configuration section for more
information.
The transmitter enters auto powerdown when the transmit buffer and shift register are empty.
The receiver enters powerdown when the following conditions are all met:
A.
B.
Receive FIFO is empty
The receiver is waiting for a start bit.
While in powerdown the Ring Indicator interrupt is still valid and transitions when the RI input
changes.
Table 46 - State of Floppy Disk Drive Interface Pins in Powerdown
nPCI_RESET
DRVDEN[0:1]
SER_IRQ
nWRTPRT
nDSKCHG
PCI_CLK
FDD PINS
nWDATA
nWGATE
nRDATA
nHDSEL
nINDEX
nMTR0
nTRK0
nSTEP
nDS0
nDIR
OUTPUT PINS
INPUT PINS
STATE IN AUTO POWERDOWN
112
Tristated
Tristated
Tristated
Tristated
Active
Active
Active
Active
Input
Input
Input
Input
Input
Unchanged
Unchanged
Unchanged