
ÉlanSC310 Microcontroller Evaluation Board User’s Manual
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The Super I/O parallel port is not connected and therefore should not be enabled.
The floppy drive interface on the Super I/O is enabled. DMA channel 2 is used
and the floppy IRQ is connected to PIRQ1 on the ÉlanSC310 microcontroller.
(Note: PIRQ1 on the ÉlanSC310 is internally set to IRQ6 when in Full ISA Bus
mode; it is programmable in all other bus modes.)
IDE Interface
An IDE drive can be directly connected to the ÉlanSC310 microcontroller. On the
evaluation board, data bit 7 is routed through the Super I/O in order to properly
handle bit 7 for I/O addresses 3F6 and 3F7, which are jointly used by the Floppy
and the IDE interface. The IRQ line from the IDE connector is connected to IRQ14
on the ÉlanSC310 microcontroller. PGP1 is used for the IDE chip select 1 (I/O
address 1f0–1F7h). PGP2 is used for IDE chip select 2 (I/O address 3f6–3f7). See
“Connecting an IDE Hard Drive” on page 1-7 for the steps to connect the drive.
Enabling the ÉlanSC310 Internal Serial Port
The ÉlanSC310 microcontroller internal serial port is typically configured as
COM1. The following ÉlanSC310 index registers need to be set for this
configuration:
• Elan Index 77h = 90h ; Enable internal UART to base address 3F8 and IRQ 4
(COM1)
• Elan Index 92h = 01h ; Enable clock to UART
• Elan Index 48h = 02h ; Set for 16C450 compatibility
• Set pin PMC2 active for all PMU modes (refer to “Power Management Control
The UART’s I/O registers 3F8h–3FFh can now be accessed to perform serial
transfers.
evalbd.book : ch4 Page 15 Thursday, August 8, 1996 2:34 PM