MB87P2020 Datasheet, PDF (348/356 Pages) Fujitsu Component Limited. – Colour LCD/CRT/TV Controller

MB87J2120, MB87P2020-A Hardware Manual
Please note that the C-API functions already include the necessary flag polling of FLNOM_CWEN.
The C-API function ’PXP_AAF’ implements the described workaround already and should be used to turn
on or off AAF within an application.
A special situation occurs when a command, which uses the AAF, is interrupted by a software reset (C-API
function ’GDC_CMD_SwRs’). In this case even a NoOp command can not ensure reinitialization of AAF.
It is necessary to execute a dummy drawing command after changing the AAF settings in order to restore
double buffered values inside AAF. Note that AAF is enabled during dummy command and the options of
the command executed before SWReset are activated. After the dummy command the new settings are ap-
plied to AAF.
Table 2-13 gives an overview and a classification about the described problem.
Table 2-13: Overview for AAFEN double buffering
Subject
Description
Classification
Effects without
workaround
Solution/Workaround
Concerned devices
Testcase
Description
The AAF double buffer for AAFEN signal works not properly.
HW limitation
The AAF settings from previous command are still valid for currently exe-
cuted command.
Workaround if no SWReset is used:
• Execute a NoOp command before AAF settings will be changed
If the drawing command with AAF is interrupted by a SWReset a special
workaround is needed:
• Execute a NoOp command after SWReset (see also chapter 2.9)
• Execute dummy draw command
MB87J2120 (Lavender)
MB87P2020 (Jasmine)
MB87P2020-A (Jasmine redesign)
Code review
2.11 Pixel Engine (PE) Commands
There are four PE commands which load rectangular shapes of bitmaps or textures to video memory.
PutTxtBM, PutTxtCP, PutBM and PutCP commands have the option to disable the write process of back-
ground data to video memory. For PutTxtBM and PutTxtCP relevant configuration is
BGCOL_EN = 0. For PutBM and PutCP it is IGNORCOL_EN = 1. In both cases situation can occur
where the data stream to video memory is finished before procession of the command is terminated. This is
the case if not transferred background or ignore-coloured pixels were generated at the end.
Due to the finished data transfer the PP output FIFOs are empty already. If the command has finished the
ready condition could be propagated to ULB command controller immediately, also if ULB has not stopped
the PE device. Resulting from this too early sent “command ready” the ULB command controller fails.
Only in the special situations with suppressed background pixels an additional {GDC_CMD_NOP();
GDC_CMD_SwRs();} command sequence is required as work around after using the described commands
with its appropriate parameters where the error may occur (example for PutTxtBM):
GDC_CMD_TxBM (xmin,xmax,ymin,ymax,FgCol,BgCol,BgEn,0,0,Lay);
GDC_FIFO_INP(p_pat, Font->Offset, 0);
if (BgEn == 0) {
GDC_CMD_NOP(); /* finish PutTxtBM without data loss */
GDC_CMD_SwRs(); /* PutTxtBM with BGCOL_EN=0 work around */
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