YTD428_07 Datasheet, PDF (11/28 Pages) YAMAHA CORPORATION – IDSU ISDN DSU for Terminal Equipment

PIN DESCRIPTIONS
-9-
s Mode Setting Section
Pin No.
33
34
35
36
37
38
39
44
45
66
82
Pin Name
TDP
RDP
ODSEL
TSMPSEL
TSMPAUT
MULTI
NTSEL
LOCAL
LPSEL
EXID
CLKSEL
I/O
Function
Remarks
HTD, LTD pulse polarity setting
IN "H": positive polarity
"L": negative polarity
with pull-up
resistor
HRD, LRD pulse polarity setting
IN "H": positive polarity
"L": negative polarity
with pull-up
resistor
T ref. pt. transmit signal setting
IN "H": HRD, LRD pins normal output
"L": HRD, LRD pins open drain
with pull-up
resistor
T ref. pt. receive data sampling timing setting
IN
"H": fixed timing (short passive bus)
When T ref. pt. data sampling mode is set to "automatic" (TSMPAUT = "L"),
set this pin to "H".
with pull-up
resistor
"L": adaptive timing (point-to-point connection, extended passive bus)
T ref. pt. data sampling mode setting
IN "H": manual setting (TSMPSEL pin state is valid)
"L": automatic setting (set TSMPSEL pin to "H")
with pull-up
resistor
T ref. pt. multiframe support setting
IN "H": support multiframe
"L": do not support multiframe
with pull-up
resistor
T ref. pt. mode setting
IN "H": NT mode
"L": TE mode (T ref. pt. I/F block operates independently of DSU block)
with pull-up
resistor
Power feeding mode setting
IN "H": phantom power feeding mode
"L": local power fedding mode
with pull-up
resistor
LPSW signal setting
IN
"H": call only extended loopback 2A
"L": normal call, call by extended loopback 2A
(loop control signal at local power feeding mode)
with pull-up
resistor
Loopback setting
IN "H": transmit ID1 = "1" (correspond to extended loopback 2)
"L": transmit ID1 = "0" (loopback 2A operates at AP = "1")
with pull-up
resistor
Clock output setting
IN "H": do not output clock
"L": output clock
with pull-up
resistor
Note 1 When not using TTL interface, set HTD, LTD pins as bellow.
When TDP = “H”, set HTD, LTD = “L”
When TDP = “L”, set HTD, LTD = “H”
Note 2 When using the YTD428 on a terminal with built-in DSU, it is recommended that fixed timing be selected for the sample
timing of T reference point receive data (TSMPSEL=“H” and TSMPAUT=“H”). This is because the bus distribution form
becomes a short passive bus in this case.
Note 3 When using NTSEL, external terminating resistor setting is required.
When NTSEL = “H”, terminating resistor is required.
When NTSEL = “L”, remove terminating resistor as necessary.
Note 4 Set LOCAL = “L” when LPSEL = “L” or CLKSEL = “L”.