You’ll need more effort to access the PCB than to install the HDDs – the partition and the large number of screws should cool a casual user’s interest in the device’s internals. So we had to unfasten the four screws that secure the PCB with partition to the remaining half of the case and then the four screws that attach the partition to the PCB. After that we could take the PCB of the DS209+ into our hands.
The PCB looks impressively large occupying almost all the free space inside the case. The blue piece of textolite carries a lot of various chips and auxiliary elements. The PCB layout is clever overall, all the components being distributed evenly on the face side of the PCB. The reverse side has some surface-mounted components, a few indicators, and connectors. The components of the DS209+ are quite unusual, by the way.
First of all, the NAS uses an MPC8533 processor from Freescale. It is thanks to this processor that the new NAS is going to conquer new performance peaks.
The marking says that this processor model incorporates an e500 core based on the PowerPC architecture.
The MPC8533 can be clocked at frequencies up to 1 gigahertz, but the NAS uses an 800MHz sample. Anyway, this is 300MHz higher than the frequency of the Marvell processor employed in the DS207+. The 800MHz processor is going to get quite hot at work, so there is an aluminum heatsink on it for additional cooling.
The DS209+ comes with as many as 512 megabytes of system memory. It would have been problematic to install so many chips on the PCB, so the developer installed a SO-DIMM slot instead.
In our sample of the NAS the slot is occupied with a module from DSL based on Elpida chips (DDR2-667MHz, CL5, 512MB). We don’t know what amount of memory the processor can address, but as we learned from its specs, the MPC8533 supports DDR2 memory with frequencies up to 533MHz only. So, we guess the employed module is not clocked at its maximum frequency.
The firmware is stored in a 4MB Spansion S29AL032D90TF103 flash memory chip because most of the OS resides on the HDD.
The two internal and one external SATA ports are supported by a Marvell 88SX7042 controller. The controller itself supports up to four SATA ports and allows uniting the connected drives into a RAID array.
The NEC D720102GC controller is responsible for all the USB ports the DS209+ offers.
The Gigabit Ethernet port is based on a 32-bit Marvell 88E8001 controller which is often installed on mainboards.
The device’s controls and indicators are based on PIC16F627A and LC4064V chips.
There is a console connector on the PCB for in-circuit programming of the latter chip but we could not find an appropriate connector for the PIC. The processor has two consoles, one of which is not installed. The missing console is JTAG while the installed one is UART.