DS80C320 Maxim, DS80C320 Datasheet - Page 3

• Manufacturer Part Number: DS80C320
• Description: The DS80C320/DS80C323 are fast 80C31/80C32-compatible microcontrollers
• Manufacturer: Maxim

Figure 1. Block Diagram
PIN DESCRIPTION
DIP
18
19
29
40
20
9
PLCC
22, 23
20
21
44
10
32
PIN
TQFP
16, 17
38
14
15
26
4
XTAL2
XTAL1
NAME
GND
RST
PSEN
V
CC
+5V (+3V for DS80C323)
Digital Circuit Ground
Reset Input. The RST input pin contains a Schmitt voltage input to
recognize external active-high reset inputs. The pin also employs an
internal pulldown resistor to allow for a combination of wired OR
external reset sources. An RC is not required for power-up, as the device
provides this function internally.
Crystal Oscillator Pins. XTAL1 and XTAL2 provide support for
parallel-resonant, AT-cut crystals. XTAL1 acts also as an input in the
event that an external clock source is used in place of a crystal. XTAL2
serves as the output of the crystal amplifier.
Program Store-Enable Output, Active Low. This signal is commonly
connected to external ROM memory as a chip enable.
active-low pulse width of 2.25 XTAL1 cycles with a period of four
XTAL1 cycles.
accessed through the bus and during a reset condition.
DS80C320/DS80C323 High-Speed/Low-Power Microcontrollers
3 of 38
PSEN
is driven high when data memory (RAM) is being
DS80C320/
DS80C323
FUNCTION
PSEN
provides an