SB16C1054_Data Sheet_EN
SB16C1054
QUAD UART WITH 256-BYTE FIFO
FEBRUARY 2009 REV 1.0
5
8
Table 2: Pin Description…continued
Name Pin Type Description
TQFP80 PLCC68
RTS0#
RTS1#
RTS2#
RTS3#
26
35
66
75
14
22
48
56
O
O
O
O
Request to Send (active low). These pins indicate that the
UART is ready to send data to the modem, and affect
transmit and receive operations only when Auto-RTS
function is enabled.
CTS0#
CTS1#
CTS2#
CTS3#
23
38
63
78
11
25
45
59
I
I
I
I
Clear to Send (active low). These pins indicate the modem
is ready to accept transmitted data from the UART, and
affect transmit and receive operations only when Auto-CTS
function is enabled.
DTR0#
DTR1#
DTR2#
DTR3#
24
37
64
77
12
24
46
58
O
O
O
O
Data Terminal Ready (active low). These pins indicate
UART is ready to transmit or receive data.
DSR0#
DSR1#
DSR2#
DSR3#
22
39
62
79
10
26
44
60
I
I
I
I
Data Set Ready (active low). These pins indicate modem is
powered-on and is ready for data exchange with UART.
DCD0#
DCD1#
DCD2#
DCD3#
19
42
59
2
9
27
43
61
I
I
I
I
Carrier Detect (active low). These pins indicate that a carrier
has been detected by modem.
RI0#
RI1#
RI2#
RI3#
18
43
58
3
8
28
42
62
I
I
I
I
Ring Indicator (active low). These pins indicate the modem
has received a ringing signal from telephone line. A low to
high transition on these input pins generates a modem
status interrupt, if enabled.
Other Interfaces
Name Pin Type Description
TQFP80 PLCC68
XTAL1 50 35 I Crystal or External Clock Input.
XTAL2 51 36 O Crystal or Buffered Clock Output.
CLKSEL 45 30 I Clock Select. This pin selects the divide-by-1 or divide-by-4
prescalable clock. During the reset, The high on CLKSEL
selects the divide-by-1 prescaler. The low on CLK selects
the divide-by-4 prescaler. The inverting value of CLKSEL is
latched into MCR[7] at the trailing edge of RESET.
RESET 53 37 I Reset (active high). This pin will reset the internal registers
and all the outputs.
VCC 5, 25, 65 13, 47, 64
I Power Supply Input. 3.3V (2.7V ~ 3.6V)
GND 16, 36, 56,
76
6, 23, 40,
57
I Signal and Power Ground.
NC 10, 30, 49,
52, 71
31 - No Internal Connection.