Reset Circuitry; Memory - Atmel AT91SAM9G45-EKES User Manual

Board Description
Two are alternatives for the SAM9G45 main clock,
One crystal and one crystal oscillator are used for the Ethernet MII/RMII chip,
One crystal is used for the AC97 codec chip, and
One crystal or one crystal oscillator is used for the TV encoder.
Table 4-1. Main Components Associated with the Clock Systems
Quantity
4.2.3

Reset Circuitry

The reset sources are:
Power on reset
Push button reset
JTAG reset from an in-circuit emulator interface.
4.2.4

Memory

4.2.4.1 External Memories
The SAM9G45 features a DDR2/LPDDR memory interface and an External Bus Interface (EBI) to permit
interfacing to a wide range of external memories and to almost any kind of parallel peripheral.
The SAM9G45-EKES board is equipped with DDR2/LPDDR devices featuring 128 MB of DDR2-
SDRAM memory (Micron MT47H64M8B6-3 16Meg*8*4).
The External Bus Interface (EBI) is connected to three kinds of memory devices:
One Parallel Flash AT49SV322DT (not populated by default)
Two DDR2-SDRAM MT47H64M8B6-3
One NAND Flash MT29F2G16ABD (not populated by default) or MT29F2G08ABD (single footprint)
The chip select NCS0, NCS1 and CS3 are used for NOR Flash, DDR2-SDRAM and NAND Flash mem-
ories, respectively. Furthermore, a dedicated jumper can disconnect each of these NCS0, NCS1, and
NCS3 signals, making them available for other functions.
4-4
6481B–ATARM–27-Nov-09
1 Crystal for Internal Clock, 12 MHz
1 Crystal for RTC Clock, 32.768 kHz
1 Oscillator for Ethernet Clock RMII, 50 MHz
1 Crystal for Ethernet Clock MII, 25 MHz
1 Crystal for AC91 Codec Clock, 24.576 MHz
Crystal for TV Encoder Clock, 13 MHz, or
1
Oscillator for TV Encoder, 13 MHz
Description Component assignment
Y1
Y2
Y4
Y5
Y3
Y7
Y6
AT91SAM9G45-EKES User Guide