Lexicon RV-8 Service Manual page 100

External Register U21 bit map
RESREGDECH is decoded from chip select CPUCS3/, write strobe CPUWRH/, and the condition
CPUADDR[3:1]==000. The result is an active high strobe when a write operation is performed at CPU
address 0x00C00000. This strobe acts as a clock signal for register device U20 on sheet 2. The following
table illustrates the register control.
15 14
D10 D11
•
CPULED6 – Test LED D10
= 0: D10 is off
= 1: D10 is lit
•
CPULED5 – Test LED D11
= 0: D11 is off
= 1: D11 is lit
•
CPULED4 – Test LED D12
= 0: D12 is off
= 1: D12 is lit
•
CPULED3 – Test LED D13
= 0: D13 is off
= 1: D13 is lit
•
CPULED2 – Test LED D14
= 0: D14 is off
= 1: D14 is lit
•
CPULED1 – Test LED D15
= 0: D15 is off
= 1: D15 is lit
•
BOOTLOCK – Program Flash Boot Sector Lock
= 0: Boot sector is write protected
= 1: Boot sector is write enabled
•
SOFTRLY – Amplifier Soft Relay
= 0: Soft Relay is open
= 1: Soft Relay is closed
External Register U20 bit map
Note that the U20 and U21 are word accesses to the same CPU address and that they are write only.
6-24
Address == 0x00C00000
13 12
D12 D13
11 10
D14 D15
RV-8 Service Manual
09 08
BOOTLOCK SOFTRLY