Specifications

Processor Configuration (V40)
OPSEL - On Chip Peripheral Selection Register
The V40 integrates several of the most common peripheral devices
with a CPU in one package. The peripheral devices include a serial
port, an interrupt controller, a DMA controller, and three
counter/timers. The OPSEL register enables or disables these
peripheral devices. The format of the OPSEL register is shown in
Figure 6-2. No restrictions are placed on the use of the OPSEL
register. The STD ROM software initializes OPSEL to a 0Eh to
enable the V40 serial port and the counter/timers for baud rate
generation.
Register: OPSEL
Address: FFFDh
76543210
DS
DMAU Select
0 Disabled
1 Enabled
IS
ICU Select
0 Disabled
1 Enabled
TS
TCU Select
0 Disabled
1 Enabled
SS
SCU Select
0 Disabled
1 Enabled
————
Figure 6–2. On Chip Peripheral Selection Register.
6-4