RX62N Datasheet, PDF (19/25 Pages) Renesas Technology Corp – 100 MHz 32-bit RX MCU with FPU, 165 DMIPS, up to 512-Kbyte Flash, Ethernet, USB 2.0

RX62N Group and RX621 Group
16-Bit SDRAM Connection and Access Examples
5.5.3 init Function
(1) Description
The init() function initializes the functions used by the microcontroller.
(2) Arguments
None
(3) Return value
None
(4) Flowchart
init
System Setup
• Set BCLK output
• Set ICLK, BCLK, and PCLK
• Set mode
Port Setup
• Set up address output pins (A23-A16)
• Set up address output pins (A15-A0)
• Set up address bus output pins (A23-A16)
• Set up data I/O output pins (D31-D08)
• Enable all SDRAM pins
• Set up SDCLK output
• Set general-purpose ports P03 and P02 data registers to 1
• Set up general-purpose ports P03 and P02 output pins
Wait for 100 µs
Note: A wait time of 100 µs is required before SDRAM
initialization due to SDRAM specifications.
External Address Space (SDRAM) Setup
Initialization sequence
• SDRAM initialization setup
• SDRAM initialization start
• Check SDRAM status
SDRAM setup
• Set SDRAM bus width
• Set mode register
• Set up auto refresh
• Set SDRAM endian mode
• Set SDRAM access mode
• Set SDRAM timing
• Set SDRAM address multiplexing
Start auto refresh
• Enable auto refresh
Enable access
• Set SDRAM to operation enabled
end
Figure 9 Flow chart (init)
R01AN0585EJ0202 Rev.2.02
Feb 14, 2014
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