AT89C5122 ATMEL [ATMEL Corporation], AT89C5122 Datasheet - Page 15

• Manufacturer Part Number: AT89C5122
• Description: MICROCONTROLLER WITH USB AND SMART CARD READER INTERFACES
• Manufacturer: ATMEL [ATMEL Corporation]

Table 2. Pin Description (Continued)
4202D–SCR–06/05
V
Port
XTAL
XTAL
VCC
P5.5
P5.6
P5.7
RST
ALE
EA/
D+
D-
REF
1
2
34
60
59
61
31
32
63
21
7
5
4
16
29
28
30
14
15
-
-
-
-
-
16
14
13
45
42
43
32
5
4
6
8
19
17
18
2
1
3
-
-
-
-
-
34
60
59
61
31
32
63
21
7
5
4
16
29
28
30
14
15
-
-
-
-
-
Internal
Supply
Power
DVCC
DVCC
AVCC
VCC
VCC
VCC
VCC
VCC
VCC
VCC
VCC
ESD
2KV
2KV
2KV
I/O
I/O
I/O
I/O
I/O
I/O
I/0
O
O
O
I
I
Reset
Level
1
1
1
Reset Input
The Port pins are driven to their reset conditions when a voltage
lower than V
This pin has an internal 10K pull-up resistor which allows the device
to be reset by connecting a capacitor between this pin and VSS.
Asserting RST when the chip is in Idle mode or Power-Down mode
returns the chip to normal operation.
The output is active for at least 12 oscillator periods when an internal
reset occurs.
USB Positive Data Upstream Port
This pin requires an external serial resistor of 27Ω (AT8xC122) or
33Ω (AT83C5123) and a 1.5 K
configuration.
USB Negative Data Upstream Port
This pin requires an external serial resistor of 27Ω (AT8xC122) or
33Ω (AT83C5123)
USB Voltage Reference: 3.0 <
V
voltage is controlled by software.
Input to the on-chip inverting oscillator amplifier
To use the internal oscillator, a crystal or an external oscillator must
be connected to this pin.
Output of the on-chip inverting oscillator amplifier
To use the internal oscillator, a crystal circuit must be connected to
this pin. If an external oscillator is used, leave XTAL2 unconnected.
External Access Enable (Only AT8xC5122)
EA must be strapped to ground in order to enable the device to fetch
code from external memory locations 0000h to FFFFh.
If security level 1 is programmed, EA will be latched on reset.
Warning : EA pin cannot be left floating. If the External Access
Enable mode is not used, EA pin must be strapped to VCC. If this last
condition is not met,the MCU may have an unpredictable behaviour.
VCC (Only AT89C5122DS)
Address Latch Enable/Program Pulse: Output pulse for latching
the low byte of the address during an access to external memory. In
normal operation, ALE is emitted at a constant rate of 1/6 (1/3 in X2
mode) the oscillator frequency, and can be used for external timing or
clocking. Note that one ALE pulse is skipped during each access to
external data memory. ALE can be disabled by setting SFR’s
AUXR.0 bit. With this bit set, ALE will be inactive during internal
fetches
REF
KB5
KB6
KB7
Alt
can be connected to D+ through a 1.5 K
IL
is applied, whether or not the oscillator is running.
Config
Reset
Port51
Port51
Port51
Push-pull
Push-pull
Push-pull
Conf 1
Ω
V
pull-up to
REF < 3.6 V
Conf 2
WPD
WPD
WPD
Input
Input
Input
V
REF for full speed
Ω
resistor. The
Conf 3
WPU
WPU
WPU
Input
Input
Input
V
Led
REF
15