Si57x-EVB
4
Rev. 0.2
1.3. Reset Circuit
The Si57x-EVB MCU may be reset by pressing momentary pushbutton SW1. It may also be held in reset by
installing a jumper at J7. MCU outputs are open drain and are tri-stated during reset. They remain tri-stated unless
otherwise directed under program control.
There is no hardware reset for the Si57x/598/599 itself. The Si57x/598/599 is reset only on power-up or through
software. Pressing the Si57x-EVB motherboard pushbutton SW1 in an attempt to reset the Si57x/598/599 may
result in unexpected behavior.
1.4. USB
A 4-pin USB receptacle is provided at location J15. The Si57x-EVB, via the MAC’s USB Function Controller, is
compatible with USB Specification 2.0. When the USB link is in use the MCU drives LED D7.
1.5. MCU
The MCU, Silicon Laboratories P/N C8051F320, provides the following functions:
Supports I
2
C communication to the DUT on behalf of the host PC per the Si57x-EVB software
Drives a number of status indicator LEDs (see Table 2)
Supplies 3.3 V to peripheral ICs on the motherboard but not to the DUT
The MCU comes pre-loaded with firmware. While there is a provision for in-circuit programming at connector J12
located on the back, this should not be necessary. The host PC operates the Si57x/598/599 software and
communicates to the Si57x/598/599 through the MCU via USB connector J15. When the USB link is in use, LED
D7 should be illuminated.
As mentioned earlier, the MCU may be reset by pressing momentary pushbutton (SW1) or held in reset by
installing a jumper at J7.
1.5.1. Status Signals
There are seven LEDs on the Si57x-EVB that report visual status as listed in Table 2 and as highlighted in Figure 2.
Upon power up, D1–D2 and only one of D3–D5 should be illuminated. D6 and D7 are only illuminated when in use.
Table 2. Si57x-EVB LEDs
Reference
Designation
Color
Signal or Status Indicated
Comments
D1
Red
5 V present
Connected to filtered 5 V
D2
Red
MCU 3.3 V present
Connected to MCU 3.3 V output
D3
Red
VREG 3.3 V selected
D4
Red
VREG 2.5 V selected
D5
Red
VREG 1.8 V selected
D6
Green OE active
D7
Green USB active
Under MCU control
Summary of Contents for Si57-EVB Series
Page 5: ...Si57x EVB Rev 0 2 5 Figure 2 Si57x EVB Motherboard LED Locations...
Page 21: ...Si57x EVB Rev 0 2 21 Figure 13 Si57x EVB MB Primary Side...
Page 22: ...Si57x EVB 22 Rev 0 2 Figure 14 Si57x EVB MB GND Plane 1...
Page 23: ...Si57x EVB Rev 0 2 23 Figure 15 Si57x EVB MB 57x_VDD Plane...
Page 24: ...Si57x EVB 24 Rev 0 2 Figure 16 Si57x EVB MB 5 3 3 V Plane...
Page 25: ...Si57x EVB Rev 0 2 25 Figure 17 Si57x EVB MB GND Plane 2...
Page 26: ...Si57x EVB 26 Rev 0 2 Figure 18 Si57x EVB MB Secondary Side...
Page 27: ...Si57x EVB Rev 0 2 27 Figure 19 Si57x EVB MB Silkscreen Side B...
Page 28: ...Si57x EVB 28 Rev 0 2 7 2 Si57x EVB Daughterboard Figure 20 Si57x EVB DB Silkscreen Side A...
Page 29: ...Si57x EVB Rev 0 2 29 Figure 21 Si57x EVB DB Primary Side...
Page 30: ...Si57x EVB 30 Rev 0 2 Figure 22 Si57x EVB DB GND Plane...
Page 31: ...Si57x EVB Rev 0 2 31 Figure 23 Si57x EVB DB 57x_VDD Plane...
Page 32: ...Si57x EVB 32 Rev 0 2 Figure 24 Si57x EVB DB Secondary Side...
Page 33: ...Si57x EVB Rev 0 2 33 Figure 25 Si57x EVB DB Silkscreen Side B...
