MB87P2020 Datasheet, PDF (77/356 Pages) Fujitsu Component Limited. – Colour LCD/CRT/TV Controller

1 Function Description
SDRAM Controller
1.1 Overview
This module is part of a graphic display controller (GDC) especially for automotive applications. The GDC
supports a set of 2D drawing functions (Pixel Processor) a video scaler interface, units for physical and di-
rect video memory access and a powerful video output stream formatter for a great variety of connectable
displays.
Inside the GDC there is a memory controller which arbitrates the internal modules and generates the re-
quired access timings for SDRAM devices. With a special address mapping and an algorithm for generating
optimized control commands the controller can derive full benefit from 4-bank-interleaving supported by
the SDRAMs. So the row activation time is hidden if switching to another memory bank in most cases. This
increases performance respective at random (non-linear) memory access. Power down modes with Clock
Suspend (CSUS) with and without SELF-Refresh are supported.¹
The SDRAM Controller arbitrates GDC internal device requests for data transfers from/to the video mem-
ory. Important is also the address calculation which controls the mapping from a given logical address (in
layer, x- and y-pixel format) to the physical bank, row and column address. Thus the other devices are in-
dependent from the physical implementation of the memory structure.
If the Application for GDC needs physical video memory (frame buffer) access, knowledge is needed how
a logical address (layer, x, y) is converted to the physical address in video memory and how this address
maps into physical host MCU address space. There is also a buffered access method without mapping into
MCU address space possible, then only internal video memory address is of interest.
DIPA
Command Controller
DQM
CMD
PP
refresh timer
Layer
Information
Arbiter
4 x 512k x 32 Bit
64M SDRAM
Address
A
D
Calculation
VIC
GPU
Intra Word
D
D
Pixel Addressing
D
Figure 1-1: SDC Block Diagram embedded into GDC
1.Jasmine implementation (GDC with integrated DRAM) makes use of an integrated single-bank
SDRAM. Therefore special features as 4 bank interleaving and power suspend/self refresh are not
supported by the device.
Function Description
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