lpc47s457-ns Standard Microsystems Corp., lpc47s457-ns Datasheet - Page 207

• Manufacturer Part Number: lpc47s457-ns
• Description: Advanced I/o With X-bus Interface
• Manufacturer: Standard Microsystems Corp.

Note:
Note 1: The default value of the DMA Channel Select register for logical device 0 (FDD) is 0x02 and for logical
Note A. Logical Device IRQ and DMA Operation
1.
a)
b)
c)
d)
e)
SMSC LPC47S45x
IRQ and DMA Enable and Disable: Any time the IRQ or DMA channel for a logical block is disabled by a register bit
in that logical block, the IRQ and/or DMA channel must be disabled. This is in addition to the IRQ and DMA
channel disabled by the Configuration Registers (active bit or address not valid).
FDC: For the following cases, the IRQ and DMA channel used by the FDC are disabled.
Digital Output Register (Base+2) bit D3 (DMAEN) set to "0".
The FDC is in power down (disabled).
Serial Ports:
Modem Control Register (MCR) Bit D2 (OUT2) - When OUT2 is a logic "0", the serial port interrupt is disabled.
Parallel Port:
Keyboard Controller: Refer to the KBD section of this spec.
SMBus Controller:
Control Register Bit D3 (ENI) – When ENI is a logic “0” the SMBus interrupt is disabled.
DMA channels are disabled if not used/selected by any Logical Device. Refer to Note A.
device 3 is 0x04.
I.
ii.
SPP and EPP modes: Control Port (Base+2) bit D4 (IRQE) set to "0", IRQ is
disabled.
ECP Mode:
(1)
(2)
(FROM ECR REGISTER)
000
001
010
011
100
101
110
111
(DMA) dmaEn from ecr register. See table below.
IRQ - See table below.
MODE
PRINTER
CONFIG
TEST
FIFO
SPP
ECP
EPP
RES
DATASHEET
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CONTROLLED BY
IRQE
IRQE
IRQE
IRQE
IRQE
IRQ
(on)
(on)
(on)
CONTROLLED BY
dmaEn
dmaEn
dmaEn
dmaEn
dmaEn
dmaEn
dmaEn
dmaEn
DMA
Rev. 08-10-09