at91sam9263 ATMEL Corporation, at91sam9263 Datasheet - Page 868

• Manufacturer Part Number: at91sam9263
• Description: At91 Arm Thumb Microcontrollers
• Manufacturer: ATMEL Corporation

43.5.2.3
868
AT91SAM9263 Preliminary
FIFO
The datapath can be characterized by two parameters: initial_latency and cycles_per_data. The
parameter initial_latency is defined as the number of LCDC Core Clock cycles until the first data
is available at the output of the datapath. The parameter cycles_per_data is the minimum num-
ber of LCDC Core clock cycles between two consecutive data at the output interface.
These parameters are different for the different configurations of the LCD Controller and are
shown in
Table 43-2.
The FIFO block buffers the input data read by the DMA module. It contains two input FIFOs to
be used in Dual Scan configuration that are configured as a single FIFO when used in single
scan configuration.
The size of the FIFOs allows a wide range of architectures to be supported.
The upper threshold of the FIFOs can be configured in the FIFOTH field of the LCDFIFO regis-
ter. The LCDC core will request a DMA transfer when the number of words in each FIFO is less
than FIFOTH words. To avoid overwriting in the FIFO and to maximize the FIFO utilization, the
FIFOTH should be programmed with:
where:
TFT
STN Mono
STN Mono
STN Mono
STN Mono
STN Color
STN Color
STN Color
STN Color
• The output interface is a 24-bit data bus. The configuration of this interface depends on the
• The configuration interface connects the datapath with the configuration block. It is used to
• The control interface connects the datapath with the timing generation block. The main
• 2048 is the effective size of the FIFO. It is the total FIFO memory size in single scan mode
• DMA_burst_length is the burst length of the transfers made by the DMA
type of LCD used (TFT or STN, Single or Dual Scan, 4-bit, 8-bit, 16-bit or 24-bit interface).
select between the different datapath configurations.
control signal is the data-request signal, used by the timing generation module to request
new data from the datapath.
and half that size in dual scan mode.
DISTYPE
FIFOTH = 2048 - (2 x DMA_BURST_LENGTH + 3)
Table
Datapath Parameters
43-2.
SCAN
Single
Single
Dual
Dual
Single
Single
Dual
Dual
Configuration
IFWIDTH
4
8
8
16
4
8
8
16
initial_latency
9
13
17
17
25
11
12
14
15
1
4
8
8
16
2
3
4
6
cycles_per_data
6249D–ATARM–20-Dec-07