Chapter 5: PROGRAMMING
The port addresses and IRQs are selected by software through a control block; the base address of the control
block is selected by jumpers. The functions within the control block are shown in the control block register map
below.
Table 5-1:
Control Block Register Map
Address
Read Function
Write Function
Base A 0
--
--
Base A 1 EEPROM Address
EEPROM Address
Base A 2
--
EEPROM Data
Base A 3
--
Load EEPROM To Registers
The addresses and IRQs of the ports are taken from an EEPROM on the board. In addition to automatically
loading them at power-on, they can be loaded by software by a write to the control block. The addresses and
interrupts are stored in the EEPROM as shown on the EEPROM address map below.
Table 5-2:
EEPROM Address Map
EEPROM Address
EEPROM Data Meaning
1
Address for Channel A
2
Address for Channel B
3
Address for Channel C
4
Address for Channel D
5
Address for Channel E
6
Address for Channel F
7
Address for Channel G
8
Address for Channel H
9
IRQ for Channel A
A
IRQ for Channel B
B
IRQ for Channel C
C
IRQ for Channel D
D
IRQ for Channels E, F, G & H
As mentioned elsewhere, the addresses entered represent A3 - A9. Therefore, the data entered is the desired
address, divided by 8.
When the board is first installed in a system, the ports are not necessarily at unused addresses. To prevent
conflicts with other devices in the system, the board has a jumper that disables the ports, next to the base
address jumpers and labeled “DF”. The control block remains enabled in this mode, allowing software to set
Manual 104-COM-8S
17