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Opcode 0x01: Write/Read Virtual Register
This command allows the host to access the contents of any of the four
virtual registers. The specific operation and register to be accessed are
determined by the command options field.
Write data is contained in the Command data field. Read data is returned
in the result field.
Command option bits affect the operation as follows:
This command cannot fail and will never set the ERR flag in the
command/response register
Opcode 0x02: Initialize Memory
This command allows the host to initialize areas of local RAM to a specific
value without incurring the overhead of writing each location via the write
memory command.
The command options field is unused and must contain 0.
The lower 8 bits of the data field contain the byte pattern to be written.
Memory starting at the address contained in VR0 and the byte count
contained in VR1 is initialized with the value contained in the lower 8 bits
of the Data field.
Note
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Bit 15 indicates read (0) or write (1) operation
Bit 14 indicates whether to access either the lower half (0) or upper
half (1) of the virtual register.
Bit 11 & 12 specify which virtual register is to be accessed (0b00 =
VR0, 0b01 = VR1, 0b10 = VR2, 0b11 = VR3).
This command does not guarantee that the memory is initialized
using any particular ordering or alignment. Do not use it to
initialize any area of memory that has alignment or ordering
requirements (e.g., device registers).
Introduction
5
5-5
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