Service manual

SERVICE MANUAL
26
1-10 IC12, 16 ALVCH16245 (16 bit Bus bidirectional transceivers)
1-11 IC13-15 ALVCH16244 (16 bit Bus Buffers)
1-12 IC17, 18 LVC244 (8 bit Bus Buffers)
1-13 IC19 LVC245 (8 bit Bus bidirectional transceivers)
In particular, this is used for changing 5V into 3.3V.
1-14 IC20 M51957B (System Reset IC. Delay time is about 0.34 sec)
1-15 IC21, 22 NJM317 (Regulator IC)
IC21: regulate +2.5V for FPGA.
IC22: regulate +1.75V for CPU.
1-16. IC23 NET2890 (USB function controllers)
1-16-2. Pin Descriptions (PU:pull-up, PD:pull-down)
Pin No. Signal name Dir Explanation
2 /SOF out Start of Frame. Active low.
3,4 DP,DM i/o USB data port. differential data.
5-11 bi-directional 8-bit data bus.
14
D[7:0] i/o
Connected with CPU for communication.
15 /CS in Chip select. Active low. (PU)
16 LCLK out buffered clock output.
17 /IOR in I/O read strobe. Active low. (PU)
18 /IOW in I/O write strobe. Active low. (PU)
19 DRQ out DMA request.
20 /DACK in DMA acknowledge. Active low. (PU)
21 /EOT in End of transfer. Active low. (PU)
22 /BUSPWR
Indicates that external logic is powered by USB bus.
in
Alternatively general input.
23 /PWRGOOD in
Indicates that external power supply used for self-powered mode is operational.
Alternatively general input.
26 /IRQ out Interrupt Request. Active low.
27 /USBOE i/o USB port output enable. Active low. (PU)
28 /DEVCFG out Device config. Alternatively general output. (PD)
30 TEST in Test. Connect this pin to ground. (PD)
32 /LRESET out Local reset. Active low. (PU)
33 /SUSP out Device suspended. Active low. (PU)
34 /WAKEUP in USB remote wakeup. Active low. (PU)
35 /RESET in External reset. (PU)
38-42 A[4:0] in Address bus.
44 CLKIN in 48 MHz Oscillator input.
45 CLKOUT out 48 MHz Oscillator output.
47 TESTOUT out Test output. Used for manufacturing test.
31 VDD_LOCAL - +3.3V or +5V DC power input for CPU I/F.
1,13,25
37,43
VDD - +3.3V DC power input for the core and USB I/F.
12,24,36
46,48
Vss - GROUND. 0V DC power return.