AT89C51AC3-RDTUM datasheet(26/143 Pages) ATMEL

26 / 143 page

AT89C51AC3

4383B–8051–01/05

Reset Value = X001 0100b

Not bit addressable

Table 8. AUXR1 Register

AUXR1 (S:A2h)

Auxiliary Control Register 1

Reset Value = XXXX 00X0b

4-2

XRS1-0

ERAM size:

Accessible size of the ERAM

XRS 2:0 ERAM size

000

256 Bytes

001

512 Bytes

010

768 Bytes

011

1024 Bytes

100

1792 Bytes

101

2048 Bytes (default configuration after reset)

110

Reserved

111

Reserved

EXTRAM

Internal/External RAM (00h - FFh)

access using MOVX @ Ri/@ DPTR

0 - Internal ERAM access using MOVX @ Ri/@ DPTR.

1 - External data memory access.

0A0

Disable/Enable ALE)

0 - ALE is emitted at a constant rate of 1/6 the oscillator frequency (or 1/3 if X2

mode is used)

1 - ALE is active only during a MOVX or MOVC instruction.

543

210

ENBOOT

GF3

DPS

Bit

Number

Bit

Mnemonic Description

7-6

Reserved

The value read from these bits is indeterminate. Do not set these bits.

5ENBOOT

Enable Boot Flash

Set this bit for map the boot Flash between F800h -FFFFh

Clear this bit for disable boot Flash.

Reserved

The value read from this bit is indeterminate. Do not set this bit.

3GF3

General-purpose Flag 3

Always Zero

This bit is stuck to logic 0 to allow INC AUXR1 instruction without affecting GF3

flag.

Reserved for Data Pointer Extension.

0DPS

Data Pointer Select Bit

Set to select second dual data pointer: DPTR1.

Clear to select first dual data pointer: DPTR0.

Bit

Number

Bit

Mnemonic Description

AT89C51AC3-RDTUM 数据表(PDF) 26 Page - ATMEL Corporation

AT89C51AC3-RDTUM 数据表(HTML) 26 Page - ATMEL Corporation

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

数据表下载

链接网址

AT89C51AC3-RDTUM 数据表(PDF) 26 Page - ATMEL Corporation

AT89C51AC3-RDTUM 数据表(HTML) 26 Page - ATMEL Corporation

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

数据表 下载

链接网址

数据表下载