Quatech DSC-200, DSC-300 Clock Rate and Optional Registers, Enable Scratchpad Register SPAD, J13

2.4 Clock Rate and Optional Registers

Figure 3 shows the jumper configuration as shipped from the factory, with two spare jumpers applied in neutral positions. Remove one or both and apply as shown in following subsections to set optional features.

J10

J11

J12

J13

X2

X4

X8

SPAD

Figure 3 --- Factory default clock rate and options settings

2.4.1 Enable Scratchpad Register (SPAD, J13)

In the default configuration, an Interrupt Status Register and an Options Register (see page 10) replace the scratchpad (base address + 7) of each UART. If the SPAD jumper is applied as in Figure 4, the UART scratchpad registers are enabled, and the Interrupt Status Register and the Options Register are not available.

J10

J11

J12

J13

X2

X4

X8

SPAD

Figure 4 --- Enable scratchpad registers

Quatech DSC-200/300 User's Manual 11