[Cryptech Core] alpha schematics

[Peter Stuge]

Fredrik Thulin wrote:
> If you want to preview

Page 13 says "PROM is write-protected by default, to disable write
protection (..), jumper must be inserted" - but FPGA_PROM_W_N can
also drive /W high to disable SPI flash write-protect.

Analog switches aren't strictly neccessary for the unidirectional
signals, but also don't cause any problem as long as their bandwidth
is high enough for the digital switching.

LED16 might be disturbingly bright with 330 Ω at 5 V. :)


Here's a Digi-Key BOM and a combined ASCII schematic and netlist for
my proposed small ARM USB controller alternative to FT232:

<pre>
U1 LPC1343FBD48,151 568-4945-ND
R1,R2 ERJ-PA3F33R0V P33.00BYCT-ND
R3 ERJ-3EKF1501V P1.50KHCT-ND
T1 DDTA114YCA-7-F DDTA114YCA-FDICT-ND
C1,C2 0603YC104JAT2A 478-3726-1-ND
C3,C4 06035A180JAT2A 478-1166-1-ND
X1 7A-12.000MAAJ-T 887-1081-1-ND

LPC_USB_VBUS U1-14 --- USB_VBUS
LPC_USB_DM U1-19 --- [R1 33R] --- USB_DM
LPC_USB_DP U1-20 --- [R2 33R] -+- USB_DP
                               |
                    +----------+
                    |
                    +-- [R3 1.5k 1%] --+
                                       |
                                     T1-3
LPC_USB_CONNECT U1-22 --- T1-1 [DDTA114YCA] T1-2 --- 3v3

LPC_TX U1-47 --- STM32_RX pin 50
LPC_RX U1-46 --- STM32_TX pin 45

LPC_XTALOUT U1-7 ---+---||--- GND
                    |   C3 18pF
        12 MHz X1 |[]|
                    |   C4 18pF
LPC_XTALIN  U1-6 ---+---||--- GND

                C1
3v3 --- U1-8 ---||--- U1-5 --- GND

3v3 --- U1-44 --||--- U1-41 -- GND
                C2

Place a jumper between U1-4 and GND for activating the LPC ROM bootloader.
</pre>

Fredrik Pavel, let me know if I need to clarify or draw something
more graphic.


//Peter