Electronic Components Datasheet Search
  English  ▼

Delete All
ON OFF
ALLDATASHEET.COM

X  

Preview PDF Download HTML

S3C4530A Datasheet(PDF) 63 Page - Samsung semiconductor

Part No. S3C4530A
Description  16/32-bit RISC microcontroller is a cost-effective, high-performance microcontroller
Download  432 Pages
Scroll/Zoom Zoom In 100% Zoom Out
Maker  SAMSUNG [Samsung semiconductor]
Homepage  http://www.samsung.com/Products/Semiconductor
Logo SAMSUNG - Samsung semiconductor

S3C4530A Datasheet(HTML) 63 Page - Samsung semiconductor

Back Button S3C4530A Datasheet HTML 59Page - Samsung semiconductor S3C4530A Datasheet HTML 60Page - Samsung semiconductor S3C4530A Datasheet HTML 61Page - Samsung semiconductor S3C4530A Datasheet HTML 62Page - Samsung semiconductor S3C4530A Datasheet HTML 63Page - Samsung semiconductor S3C4530A Datasheet HTML 64Page - Samsung semiconductor S3C4530A Datasheet HTML 65Page - Samsung semiconductor S3C4530A Datasheet HTML 66Page - Samsung semiconductor S3C4530A Datasheet HTML 67Page - Samsung semiconductor Next Button
Zoom Inzoom in Zoom Outzoom out
 63 / 432 page
background image
S3C4530A
INSTRUCTION SET
3-21
RESERVED BITS
Only twelve bits of the PSR are defined in ARM7TDMI (N, Z, C, V, I, F, T & M[4:0]); the remaining bits are
reserved for use in future versions of the processor. Refer to Figure 2-6 for a full description of the PSR bits.
To ensure the maximum compatibility between ARM7TDMI programs and future processors, the following rules
should be observed:
— The reserved bits should be preserved when changing the value in a PSR.
— Programs should not rely on specific values from the reserved bits when checking the PSR status, since they
may read as one or zero in future processors.
A read-modify-write strategy should therefore be used when altering the control bits of any PSR register; this
involves transferring the appropriate PSR register to a general register using the MRS instruction, changing only
the relevant bits and then transferring the modified value back to the PSR register using the MSR instruction.
Examples
The following sequence performs a mode change:
MRS
R0,CPSR
; Take a copy of the CPSR.
BIC
R0,R0,#0x1F
; Clear the mode bits.
ORR
R0,R0,#new_mode
; Select new mode
MSR
CPSR,R0
; Write back the modified CPSR.
When the aim is simply to change the condition code flags in a PSR, a value can be written directly to the flag
bits without disturbing the control bits. The following instruction sets the N, Z, C and V flags:
MSR
CPSR_flg,#0xF0000000
; Set all the flags regardless of their previous state
; (does not affect any control bits).
No attempt should be made to write an 8 bit immediate value into the whole PSR since such an operation cannot
preserve the reserved bits.
INSTRUCTION CYCLE TIMES
PSR transfers take 1S incremental cycles, where S is defined as sequential (S-cycle).


Html Pages

1  2  3  4  5  6  7  8  9  10  11  12  13  14  15  16  17  18  19  20  21  22  23  24  25  26  27  28  29  30  31  32  33  34  35  36  37  38  39  40  41  42  43  44  45  46  47  48  49  50  51  52  53  54  55  56  57  58  59  60  61  62  63  64  65  66  67  68  69  70  71  72  73  74  75  76  77  78  79  80  81  82  83  84  85  86  87  88  89  90  91  92  93  94  95  96  97  98  99  100   ...More


Datasheet Download

Go To PDF Page


Link URL




Privacy Policy
ALLDATASHEET.COM
Does ALLDATASHEET help your business so far?  [ DONATE ]  

About Alldatasheet   |   Advertisement   |   Datasheet Upload   |   Contact us   |   Privacy Policy   |   Alldatasheet API   |   Link Exchange   |   Manufacturer List
All Rights Reserved© Alldatasheet.com


Mirror Sites
English : Alldatasheet.com  |   English : Alldatasheet.net  |   Chinese : Alldatasheetcn.com  |   German : Alldatasheetde.com  |   Japanese : Alldatasheet.jp
Russian : Alldatasheetru.com  |   Korean : Alldatasheet.co.kr  |   Spanish : Alldatasheet.es  |   French : Alldatasheet.fr  |   Italian : Alldatasheetit.com
Portuguese : Alldatasheetpt.com  |   Polish : Alldatasheet.pl  |   Vietnamese : Alldatasheet.vn