MB87P2020 Datasheet, PDF (59/356 Pages) Fujitsu Component Limited. – Colour LCD/CRT/TV Controller

User Logic Bus
CMDDEB MCU read command MCU write command
MCU write_valid
FIFO write_valid
FIFO write data
Command Register (CMD)
Command decoder
Command
Controller
Input FIFO (IFIFO)
Command Shadow Register
shadow_valid
Command start
Command stop
Command ready
Command reset
Command Instruction
Parameter
Code
FIFO read
FIFO space
FIFO empty
FIFO space
for execution devices
FIFO empty
for execution devices
FIFO read
from execution devices
Figure 1-11: Command execution within ULB
FIFO read data
for execution devices
Additionally the write event of a new command triggers a mechanism that is responsible for dividing data
between different commands. This allows to write data for next command into input FIFO while the current
command is still running and the selected execution device reads data from FIFO.
Note: For the programmer it is important not to write data for currently executed com-
mand after writing a new command because these data would be interpreted as
data for new command.
After the currently running command has finished and all data in input FIFO have been processed the ULB
command controller writes next command into shadow register and sets ’CMD_WR_EN=1’.
Lavender differs between read and write commands. For commands reading data from display controller
via output FIFO for Lavender an additional condition has to be met before execution of a new command is
started.
Note: For a Lavender read command output FIFO has to be empty before a new com-
mand is started. In Jasmine this additional condition need not be respected and the
output FIFO can collect data from different commands.
Two different error cases regarding the ULB command controller can be observed by MCU via special error
flags (FLNOM_ECODE, FLNOM_EDATA). A detailed description of flags regarding the command execution
can be found in chapter 1.5.5.
1.5.4 Display controller commands
Display controller commands for Lavender and Jasmine are divided per execution type into infinite, finite
and special commands. An additional subdivision can be made into write and read commands independent
from execution type (finite or infinite). For a detailed command list see appendix.
Infinite command execution is processed as described in section 1.5.3. The stop condition for infinite com-
mands is the writing of next command. Infinite commands are:
• PutPA, DwLine, DwRect, PutPixel, PutPxWd, PutPxFC, GetPixel, XChPixel, MemCP
and DwPoly
Functional description
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