DIGITAL-LOGIC MICROSPACE MSEP800, Technical User'S Manual

Page: 112 / 140

DIGITAL-LOGIC AG
MSEP800 Manual V1.0G
112
12.2.5 Serial Interface Control Register
A serial interface register controls the I/O address and interrupt number of two 16C550 compatible Universal
Asynchronous Receiver and Transmitter (UART). This configurations is overdriven with the eight jumpers on
connector J27.
This feature COM3/4 is not available on all MSEP800 versions.
COM_CTRL
COM Control Register
I/O address 0242h
Type Write only
Default value 01 100 101b if no jumper is connected to J27
The default configuration is
COM_CTRL[7:6] = 01 => I/O address COM C: 3E8 and COM D: 2E8
COM_CTRL[5:3] = 100 => Interrupt COM C: IRQ 10
COM_CTRL[2:0] = 101 => Interrupt COM D: IRQ 11
COM C&D I/O address select
The COM Control Register select the I/O address of COM ports C&D.
Bit
Function Value I/O address COM C I/O address COM D
00 03F8-03FF COM1 02F8-02FF COM2
01 03E8-03EF COM3 02E8-02EF COM4
10 0338-033F COM5 0238-023F COM6
7:6 Serial port I/O address
select
11 0390-0397 COM7 0398-039F COM8
5:3 COM_C interrupt See COM C serial port interrupt table
2:0 COM_D interrupt See COM D serial port interrupt table
COM C serial port interrupt table
COM D serial port interrupt table
The COM Control Register select the interrupt number of COM ports C&D.
COM_CTRL COM_CTRL
bit bit
Interrupt IRQ
[5] [4] [3]
Interrupt IRQ
[2] [1] [0]
IRQ 3 0 0 0 IRQ 3 0 0 0
IRQ 4 0 0 1 IRQ 4 0 0 1
IRQ 5 0 1 0 IRQ 5 0 1 0
IRQ 7 0 1 1 IRQ 7 0 1 1
IRQ 10 1 0 0 IRQ 10 1 0 0
IRQ 11 1 0 1 IRQ 11 1 0 1
IRQ 15 1 1 0 IRQ 15 1 1 0
none [Z] 1 1 1 none [Z] 1 1 1
A transition from low to high of the INTC or INTD interrupt from the UART generates a active low pulse
during one clock (1.8MHz, 560ns) at the selected IRQ line. When deasserted the IRQ lines are tristated and
the interrupts could be shared.
Older CPLD versions than 1-1 have a shift by one interrupt table:
none[Z]:000, IRQ 3:001, IRQ 4:010, IRQ 5:011, IRQ 7:100, IRQ 10:101, IRQ 11:110, IRQ 15:111
ATTENTION!
You have to reserve the selected IRQ for ISA (for COM3 and COM4) in the bios setup.
(-> Motherboard Device Configuration -> LPC Card Devices)
You have to check if the selected IRQ are not in use by the “PCI Interupt Steering”, otherwise you
have to change this IRQs.
(-> Motherboard Device Configuration -> PCI Configuration -> PCI Interupt Steering