Intel 8xC251TB User Manual
Page 5
273138-002 December 2003 v
8xC251Tx Hardware Description
8xC251TB, 8xC251TQ Hardware Description
Addendum to the 8xC251SA, 8xC251SB, 8xC251SP, 8xC251SQ, User’s Manual
1.0 INTRODUCTION TO THE 8xC251Tx
1.1
Comparing the 8xC251Tx and 8xC251Sx ..................................................................... 1
2.0 SIGNAL SUMMARY
3.0 THE SECOND SERIAL I/O PORT
3.1
Overview........................................................................................................................ 7
3.2
Special Function Register Definitions ............................................................................ 9
3.2.1
SCON1 .................................................................................................................... 9
3.2.2
SBUF1 ................................................................................................................... 10
3.2.3
SADDR1 ................................................................................................................ 10
3.2.4
SADEN1 ................................................................................................................ 10
3.2.5
BGCON .................................................................................................................. 10
3.2.6
IE1 ......................................................................................................................... 11
3.2.7
IPH1 ....................................................................................................................... 11
3.2.8
IPL1 ....................................................................................................................... 11
4.0 EXTENDED DATA FLOAT TIMING
4.1
Summary of the Extended Data Float Timing Changes .............................................. 12
FIGURES
Figure 1
8xC251Tx Block Diagram ..................................................................................... 1
TABLES
Table 1.
8xC251Tx Signal Summary ................................................................................. 2
Table 2.
8xC251Tx Signal Descriptions ............................................................................. 3
Table 3.
Special Function Register (SFR) Map.................................................................. 6
Table 4.
Second Serial I/O Port Signals ............................................................................ 7
Table 5.
Second Serial I/O Port Special Function Registers.............................................. 8
Table 6.
SCON1 Special Function Register Definitions ..................................................... 9
Table 7.
BGCON Special Function Register Definitions .................................................. 10
Table 8.
IE1 Special Function Register Definitions .......................................................... 11
Table 9.
IPH1 Special Function Register Definitions ....................................................... 11
Table 10.
IPL1 Special Function Register Definitions ........................................................ 11
Table 11.
Interrupt Priority of Second Serial I/O Port......................................................... 11
Table 12.
UCONFIG1 bit definitions for the 8xC251Tx ...................................................... 12
Table 13.
Summary of the EDF# and WSB#[1:0] Configuration Options........................... 13