EVAL-ADUC831QSZ Datasheet, PDF (31/76 Pages) Analog Devices – MicroConverter®, 12-Bit ADCs and DACs with Embedded 62 kBytes Flash MCU

ADuC831 Configuration SFR (CFG831)
The CFG831 SFR contains the necessary bits to configure the
internal XRAM, EPROM controller, PWM output selection
and frequency, DAC buffer, and the extended SP. By default it
configures the user into 8051 mode, i.e., extended SP is disabled,
internal XRAM is disabled.
CFG831
SFR Address
Power-On Default Value
Bit Addressable
ADuC831 Config SFR
AFH
10*H
No
ADuC831
Bit Name
7
EXSP
6
PWPO
5
DBUF
4
EPM2
3
EPM1
2
EPM0
1
RSVD
0
XRAMEN
Table VIII. CFG831 SFR Bit Designations
Description
Extended SP Enable.
When set to “1” by the user, the stack will rollover from SPH/SP = 00FFH to 0100H.
When set to “0” by the user, the stack will roll over from SP = FFH to SP = 00H.
PWM Pin Out Selection.
Set to “1” by the user = PWM output pins selected as P3.4 and P3.3.
Set to “0” by the user = PWM output pins selected as P2.6 and P2.7.
DAC Output Buffer.
Set to “1” by the user = DAC_. Output Buffer Bypassed.
Set to “0” by the user = DAC Output Buffer Enabled.
Flash/EE Controller and PWM Clock Frequency Configuration Bits.
Frequency should be configured such that Fosc/Divide Factor = 32 kHz + 50%.
EPM2 EPM1 EPM0
Divide Factor
0
00
32
0
01
64
0
10
128
0
11
256
1
00
512
1
01
1024
Reserved. This bit should always contain 0.
XRAM Enable Bit.
When set to “1” the internal XRAM will be mapped into the lower 2 kBytes of the external address space.
When set to “0” the internal XRAM will not be accessible and the external data memory will be mapped
into the lower 2 kBytes of external data memory.
*Note that the Flash/EE controller bits EPM2, EPM1, EPM0 are set to their
correct values depending on the crystal frequency at power-up. The user should
not modify these bits so all instructions to the CFG831 register should use the
ORL, XRL, or ANL instructions. Value of 10H is for a 11.0592 MHz crystal.
REV. 0
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