Toshiba ESTUDIO170F, Service Manual

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e-STUDIO170F Circuit Description January 2005 © TOSHIBA TEC
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• ASIC (I/O port: IC38) Signal Table
Pin No. Signal name I/O Function
1, 25, 41, 52, 61 VDD - +5V
2-9 D[0]-[7] I/O Data bus
10, 34, 42, 46, 51,
56, 60, 71
VSS - Signal ground
11 IOPTX I ASIC (I/O port) chip select signal (Low-active)
Selects the ASIC (I/O port).
12 HIOWX I I/O write signal (Low-active)
Writes data to each IC and I/O device.
13 HIORX I I/O read signal (Low-active)
Reads data into each IC and I/O device.
14-16 A[1]-[3] I Address bus
17 HSWC0 - Pull-down: signal ground
18 DDETO I Document detect signal (Low-active)
Detects the presence or absence of a document.
19 CIREQ I CI request signal (Low-active)
Indicates that the Sub-CPU (IC56) has detected the CI
signal.
20 HSWC3 - Pull-down: signal ground
21 PWRSVREQ I Super power save request signal (Low-active)
Requests the Sub-CPU to move to the Super Power
Save mode.
22 HSWC5 - Pull-down: signal ground
23 HSWC6 - Pull-down: signal ground
24 HSWC7 - Pull-up: +5V
26-28 SPVOL0-2 O Speaker volume control signal
Controls the volume of the speaker.
29 RING/TONE O Ring/tone select signal (H: Pseudo ring, L: Tone)
Selects the signal to be output from the speaker.
30 MDM1RESX O MODEM reset signal (Low-active)
Resets the MODEM (IC53).
31 TONESEL O Line/tone select signal (H: Line monitor, L: Ring or
tone)
Selects the signal to be output from the speaker.
32, 33 HSWS6, 7 - Not used (Open)
35 CISXO I CI detect signal (L: Detected)
Detects the ring signal sent from the contacted commu-
nication station.
36 REVAO I Line current detect signal
Detect current flowing through the line.
37 REVBO I Current reverse line current detect signal
Detect current flowing through the line.
38 HOOKO I Hook detect signal (H: On-hook, L: Off-hook)
Detects the hook status of the handset.
39 EXTHK I External TEL hook detect signal (H: On-hook, L: Off-
hook)
Detects the hook status of the external TEL.
40 HSER5 - Pull-down: signal ground
43 LEDBLK O Power save LED blinking signal
Requests the Sub-CPU to blink the power save LED.
44 PWRSVACK O Power save acknowledge signal (Low-active)
Enables the Sub-CPU to move to the Super Power
Save mode.
45 PRTRESX O Printer reset signal (Low-active)
Resets the Engine-CPU.
47 CPRDYX O Controller power ready signal (Low-active)
The ASIC (I/O port) indicates to the Engine-CPU that
sending and receiving of signals is ready.