NEC uPD72257, Preliminary User'S Manual

Page: 209 / 343

7.7.2.6 VOnLCDUPCURR - Current address register
This register contains an approximate value of the currently used pixel data
address.
This register is loaded with the framebuffer start address, i.e. from
VOnLCDUPBASE, with the beginning of each frame output and incremented
when the DMA function transfers new data from the framebuffer to the FIFO.
Access
This register can be read in 32-bit units.
Address <VOn_Base> + 02C
H
Initial Value
0000 0000
H
. This register is initialized by any reset.
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
UPCURRADDR[31:16]
R
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
UPCURRADDR[15:0]
R
Bit Bit name Function
31 to 0
UPCURRADDR
[31:0]
Approximate current pixel data address
Note The VOnLCDUPCURR value may change at any moment, and is not normally
read. It can be read to determine the approximate position within the framebuffer
or for test purposes.
Video Output Chapter 7
Preliminary User's Manual S19203EE1V3UM00
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