MB87P2020 Datasheet, PDF (60/356 Pages) Fujitsu Component Limited. – Colour LCD/CRT/TV Controller

MB87J2120, MB87P2020-A Hardware Manual
In difference to infinite commands for finite commands the amount of data to be processed is fixed. It is
defined by various register settings inside the execution devices or command coded parameters in case of
GetPA (CMD_PAR).
Finite commands are:
• PutBM, PutCP, PutTxtBM, PutTxtCP, GetPA
Special commands are control commands influencing the command execution itself or execution devices
but they do not process data. There are two special commands:
• Software reset (SwReset) and No Operation (NoOp)
The NoOp command is included in the normal command execution pipeline as described in section 1.5.3
with the exception that no execution device is activated and no data are read from input FIFO or written to
output FIFO. This command can be used to force the previous command to end data processing. Note that
all data send during NoOp command is active are kept for next command.
The SwReset command treats as a synchronous reset for command execution. This command is not in-
cluded in the normal command pipeline and is executed immediately. The Command Controller inside ULB
and also all execution devices (complete PP, AAF and IPA inside DIPA) go in its initial state, the command
pipeline will be emptied and the FIFOs will be reset so that all data will be lost.
Note: During SwReset input- and output FIFO will be reset so that data loss will occur.
Not affected by software reset are display controller parts not responsible for command execution (SDC,
VIC, GPU, DPA inside DIPA, CU, CCFL and parts of ULB). These devices continue running and process-
ing data. To reset these devices a hardware reset is necessary¹.
Due to a not interruptible SDRAM access software reset is not completed in one clock and needs execution
time depending on running SDRAM access for PP or IPA. Therefore the command flow control has also to
be used by an application after software reset.
Note: Also after SwReset the flag FLNOM_CWEN has to be polled in order to ensure a
save reset operation and execution of following commands.
1.5.5 Registers and flags regarding command execution
In order to allow an application controlling and watching the command execution ULB contains some flags
(within flag register) to provide the following functions:
• Flag: FLNOM_CWEN
Watching the command execution state as already described in section 1.5.3
• Flags: FLNOM_RIPA, FLNOM_RMCP, FLNOM_RMAU, FLNOM_RPE, FLNOM_BIPA, FLNOM_BMCP,
FLNOM_BMAU, FLNOM_BPE
Watching the state (busy or ready) of a specific execution device. Because all flags are high active both
variants are offered by display controller to capture the needed event (busy or ready).
• Flag: FLNOM_ECODE
A wrong command code was sent to display controller. The wrong code is treated internally as a NoOP
command which means that the command controller simply waits for a new command and no data
processing is performed. All data sent to input FIFO are kept for next command as an exception for
NoOp command behaviour.
• Flag: FLNOM_EDATA
This error flag is set when an execution device tries to read data from an empty input FIFO. This may
indicate a malfunction of execution device but the interpretation of this flag heavily depends on execu-
tion device implementation.
All flags are handled as described in section 1.6 and all are able to cause an interrupt if required. A detailed
flag description of all display controller flags can be found in flag description located in appendix.
1. A hardware reset can also be triggered by software by set register CLKPDR_MRST to ’1’.
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