3 - 2
35
EA
Input
N/A
External Access
. This pin determines where the 8051 fetches
code between addresses 0x0000 and 0x1FFF. If EA = 0 the 8051
fetches this code from its internal RAM. IF EA = 1 the 8051 fetches
this code from external memory.
12
11
12
5
XTALIN
Input
N/A
Crystal Input
. Connect this signal to a 24-MHz parallel-resonant,
fundamental mode crystal and 20-pF capacitor to GND.
It is also correct to drive XTALIN with an external 24 MHz square
wave derived from another clock source.
11
10
11
4
XTALOUT
Output
N/A
Crystal Output
. Connect this signal to a 24-MHz parallel-resonant,
fundamental mode crystal and 20-pF capacitor to GND.
If an external clock is used to drive XTALIN, leave this pin open.
1
100
5
54
CLKOUT
O/Z
12 MHz 12-, 24- or 48-MHz clock, phase locked to the 24-MHz input clock.
The 8051 defaults to 12-MHz operation. The 8051 may tri-state this
output by setting CPUCS.1 = 1.
Port A
82
67
40
33
PA0 or
INT0#
I/O/Z
I
(PA0)
Multiplexed pin whose function is selected by:
PORTACFG.0
PA0
is a bidirectional IO port pin.
INT0#
is the active-LOW 8051 INT0 interrupt input signal, which is
either edge triggered (IT0 = 1) or level triggered (IT0 = 0).
83
68
41
34
PA1 or
INT1#
I/O/Z
I
(PA1)
Multiplexed pin whose function is selected by:
PORTACFG.1
PA1
is a bidirectional IO port pin.
INT1#
is the active-LOW 8051 INT1 interrupt input signal, which is
either edge triggered (IT1 = 1) or level triggered (IT1 = 0).
84
69
42
35
PA2 or
SLOE
I/O/Z
I
(PA2)
Multiplexed pin whose function is selected by two bits:
IFCONFIG[1:0].
PA2
is a bidirectional IO port pin.
SLOE
is an input-only output enable with programmable polarity
(FIFOPOLAR.4) for the slave FIFOs connected to FD[7..0] or
FD[15..0].
85
70
43
36
PA3 or
WU2
I/O/Z
I
(PA3)
Multiplexed pin whose function is selected by:
WAKEUP.7 and OEA.3
PA3
is a bidirectional I/O port pin.
WU2
is an alternate source for
USB Wakeup,
enabled by WU2EN
bit (WAKEUP.1) and polarity set by WU2POL (WAKEUP.4). If the
8051 is in suspend and WU2EN = 1, a transition on this pin starts
up the oscillator and interrupts the 8051 to allow it to exit the sus-
pend mode. Asserting this pin inhibits the chip from suspending, if
WU2EN=1.
89
71
44
37
PA4 or
FIFOADR0
I/O/Z
I
(PA4)
Multiplexed pin whose function is selected by:
IFCONFIG[1..0].
PA4
is a bidirectional I/O port pin.
FIFOADR0
is an input-only address select for the slave FIFOs con-
nected to FD[7..0] or FD[15..0].
90
72
45
38
PA5 or
FIFOADR1
I/O/Z
I
(PA5)
Multiplexed pin whose function is selected by:
IFCONFIG[1..0].
PA5
is a bidirectional I/O port pin.
FIFOADR1
is an input-only address select for the slave FIFOs con-
nected to FD[7..0] or FD[15..0].
91
73
46
39
PA6 or
PKTEND
I/O/Z
I
(PA6)
Multiplexed pin whose function is selected by the IFCONFIG[1:0]
bits.
PA6
is a bidirectional I/O port pin.
PKTEND
is an input-only packet end with programmable polarity
(FIFOPOLAR.5) for the slave FIFOs connected to FD[7..0] or
FD[15..0].
Table 4-1. FX2 Pin Descriptions
[5]
(continued)
128
TQFP
100
TQFP
56
SSOP
56
QFN
Name
Type
Default
Description
PIN DESCRIPTIONS OF IC CY7C68013