W65C21S Datasheet, PDF (3/16 Pages) List of Unclassifed Manufacturers – Peripheral Interface Adapter (PIA)

The Western Design Center, Inc.
DESCRIPTION
The WDC W65C21S is a very flexible Peripheral Interface
Adapter (PIA) for use with WDC’s 65xx and other 8-bit
microprocessor families. The W65C21S provides
programmed microprocessor control of up to two peripheral
devices (Port A and Port B). Peripheral device control is
accomplished through two 8-bit bidirectional I/O Ports, with
individually designed Data Direction Registers. The Data
Direction Registers provide selection of data flow direction
(input or output) at each respective I/O Port. Data flow
direction may be selected on a line-by-line basis with
intermixed input and output lines within the same port. The
“handshake” interrupt control feature is provided by four
peripheral control lines. This capability provides enhances
control over data transfer functions between the
microprocessor and peripheral devices, as well as
bidirectional data transfer between W65C21S Peripheral
Interface Adapters in multiprocessor systems.
W65C21S Data Sheet
• Low Power CMOS N-well silicon gate technology
• High speed/Low power replacement for
Motorola/Rockwell/AMI/MOS
Technologies/MOSTEK/HITACHI/ ST
Microelectronics/GTE/CMD 6520, 6521, 6820,
6821 PIA’s
• Two 8-bit bidirectional I/O ports with individual
data direction control.
• Automatic “Handshake” control of data transfers
• Two interrupts (one for each port) with program
control
• Static to 14MHz operation, with high speed Port A,
CA2 outputs.
• Industrial temperature range
• 40 Pin Plastic Dip and 44 Pin Plastic PLCC
versions
• 5 volt ± 10% supply requirements
• Compatible with the 65xx and 68xx family of
microprocessors
PA4 ₇
PA5 ₈
PA6 ₉
PA7 ₁₀
PB0 ₁₁
PB1 ₁₂
PB2 ₁₃
PB3 ₁₄
PB4 ₁₅
PB5 ₁₆
PB6 ₁₇
W65C21S
39 RS0
38 RS1
37 RESB
36 D0
35 D1
34 D2
33 D3
32 D4
31 D5
30 D6
29 D7
VSS 1
PA0 2
PA1 3
PA2 4
PA3 5
PA4 6
PA5 7
PA6 8
PA7 9
PB0 10
PB1 11
PB2 12
PB3 13
PB4 14
PB5 15
PB6 16
PB7 17
CB1 18
CB2 19
VCC 20
40
CA1
39
CA2
38 IRQAB
37 IRQBB
36
RS0
35
RS1
34 RESB
33
D0
32
D1
31
D2
30
D3
29
D4
28
D5
27
D6
26
D7
25
PHI2
24
CS1
23 CS2B
22
CS0
21
RWB
Figure 1. 44 Pin PLCC Pin Configuration
Figure 2. 40 Pin DIP Pin Configuration
FEATURES
The Western Design Center
W65C21S
3