11-1
CHAPTER 11
MINIMUM HARDWARE SETUP
This chapter discusses the basic operating requirements of the MCS
®
251 microcontroller and de-
scribes a minimum hardware setup. Topics covered include power, ground, clock source, and de-
vice reset. For parameter values, refer to the device data sheet.
11.1 MINIMUM HARDWARE SETUP
Figure 11-1 shows a minimum hardware setup that employs the on-chip oscillator for the system
clock and provides power-on reset. Control signals and Ports 0, 1, 2, and 3 are not shown. See
sections 11.3, “Clock Sources” and 11.4.4, “Power-on Reset.”
Figure 11-1. Minimum Setup
8XC251S
x
A4141-02
XTAL2
V
SS
V
CC
V
CC
XTAL1
RST
C1
V
SS1
C2
1µF
+
Note:
V
CC2
is a secondary power pin that reduces power supply noise. V
SS1
and V
SS2
are
secondary ground pins that reduce ground bounce and improve power supply by-passing.
Connections to these pins are not required for proper device operation.
V
CC2
V
SS2
Summary of Contents for 8XC251SA
Page 2: ......
Page 3: ...May 1996 8XC251SA 8XC251SB 8XC251SP 8XC251SQ Embedded Microcontroller User s Manual...
Page 18: ......
Page 19: ...1 Guide to This Manual...
Page 20: ......
Page 30: ......
Page 31: ...2 Architectural Overview...
Page 32: ......
Page 41: ...3 Address Spaces...
Page 42: ......
Page 63: ...4 Device Configuration...
Page 64: ......
Page 81: ...5 Programming...
Page 82: ......
Page 102: ......
Page 103: ...6 Interrupt System...
Page 104: ......
Page 120: ......
Page 121: ...7 Input Output Ports...
Page 122: ......
Page 132: ......
Page 133: ...8 Timer Counters and Watchdog Timer...
Page 134: ......
Page 153: ...9 Programmable Counter Array...
Page 154: ......
Page 170: ......
Page 171: ...10 Serial I O Port...
Page 172: ......
Page 187: ...11 Minimum Hardware Setup...
Page 188: ......
Page 197: ...12 Special Operating Modes...
Page 198: ......
Page 206: ......
Page 207: ...13 External Memory Interface...
Page 208: ......
Page 239: ...14 Programming and Verifying Nonvolatile Memory...
Page 240: ......
Page 250: ......
Page 251: ...A Instruction Set Reference...
Page 252: ......
Page 390: ......
Page 391: ...B Signal Descriptions...
Page 392: ......
Page 400: ......
Page 401: ...C Registers...
Page 402: ......
Page 436: ......
Page 437: ...Glossary...
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Page 446: ......
Page 447: ...Index...
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