41CL User Manual
© 2019, Systemyde International Corporation
30
entire 4K block of RAM memory starting at the address specified in the address field.
The address field is truncated to create an address that is on a 4K boundary before the
writes commence. Only memory addresses are valid for this function, and a
DATA
ERROR
message will result if an I/O address is specified. The
YMCLR
function cannot
be used to write to physical modules.
The figure below shows the formatting required for the address and data in the ALPHA
register for the
YMCLR
function.
ALPHA register
11
10
9
8
7
6
5
4
3
2
1
physical address
P5 P4 P3 P2 P1 P0
-
D3 D2 D1 D0
logical address
L3 L2 L1 L0
-
B
-
D3 D2 D1 D0
YMCPY
(starting address pair in ALPHA register)
Executing
YMCPY
(
Copy Memory Block
) copies the contents of one 4K block of
memory (Flash or RAM) to another 4K block of RAM memory. This function only
allows copying blocks of memory that start on 4K boundaries and are 4K in length. Only
memory addresses are valid for this function, and
DATA ERROR
will result if an I/O
address is specified.
When executed from the keyboard a
COPYING
message is written to the display during
the actual transfers. These transfers are executed in 50x Turbo mode.
If the MMU is not enabled for a source logical address specified with the
YMCPY
func-
tion, the data is fetched from a physical module and copied to internal memory. In this
case the bank identifier is ignored, because the physical module will be in control of the
bank select. This means that only Bank 1 of the module can be copied to memory.
This function can be used to write to a physical Port. In this case the function uses the
WROM instruction, which only writes 10 bits.
The
YMCPY
function is ideal for creating backups of system information such as the
41C register memory or the MMU contents. To backup the 41C register memory
(including all user programs) simply copy the contents of memory starting at address
0x800000 to an available block of RAM. Use address 0x804000 to backup the MMU
configuration.
The figure below shows the formatting required for the address and data in the ALPHA
