AT89C5122 ATMEL [ATMEL Corporation], AT89C5122 Datasheet - Page 24

• Manufacturer Part Number: AT89C5122
• Description: MICROCONTROLLER WITH USB AND SMART CARD READER INTERFACES
• Manufacturer: ATMEL [ATMEL Corporation]

Registers
24
AT8xC5122/23
Table 5. Auxiliary Register - AUXR (8Eh)
Reset Value = 0XXX X000b
Number
Bit
DPU
6-3
7
2
1
0
7
Mnemonic Description
EXTRAM
XRS0
DPU
Bit
AO
-
6
-
Disable weak Pull-up
Reserved
The value read from this bit is indeterminate. Do not change these bits.
XRAM Size
EXTRAM bit
Cleared to access internal XRAM using MOVX @ Ri/ @ DPTR.
Set to access external memory.
Programmed by hardware after Power-up regarding Hardware Security Byte
(HSB), default setting , XRAM selected.
ALE Output bit
Cleared , ALE is emitted at a constant rate of 1/6 the oscillator frequency (or 1/3 if
X2 mode is used)(default).
Set , ALE is active only when a MOVX or MOVC instruction is used.
0
1
0
1
5
-
4
-
weak pull-up is enabled
weak pull-up is disabled
256 bytes (default)
512 bytes
3
XRS0
2
EXTRAM
1
4202D–SCR–06/05
AO
0