ADUC7029 Analog Devices, ADUC7029 Datasheet - Page 52

• Manufacturer Part Number: ADUC7029
• Description: Precision Analog Microcontroller, 12-Bit Analog I/O, ARM7TDMI MCU
• Manufacturer: Analog Devices

Specifications of ADUC7029

• Mcu Core: ARM7 TDMI
• Mcu Speed (mips): 40
• Sram (bytes): 8152Bytes
• Gpio Pins: 22
• Adc # Channels: 7

ADuC7019/20/21/22/24/25/26/27/28/29
OTHER ANALOG PERIPHERALS
DAC
The ADuC7019/20/21/22/24/25/26/27/28/29 incorporate two,
three, or four 12-bit voltage output DACs on-chip, depending on
the model. Each DAC has a rail-to-rail voltage output buffer
capable of driving 5 kΩ/100 pF.
Each DAC has three selectable ranges: 0 V to V
band gap 2.5 V reference), 0 V to DAC
DAC
The signal range is 0 V to AV
MMRs Interface
Each DAC is independently configurable through a control
register and a data register. These two registers are identical for
the four DACs. Only DAC0CON (see Table 50) and DAC0DAT
(see Table 52) are described in detail in this section.
Table 49. DACxCON Registers
Name
DAC0CON
DAC1CON
DAC2CON
DAC3CON
Table 50. DAC0CON MMR Bit Designations
Bit
7:6
5
4
3
2
1:0
REF
Name
DACCLK
DACCLR
is equivalent to an external reference for the DAC.
Address
0xFFFF0600
0xFFFF0608
0xFFFF0610
0xFFFF0618
Value
00
01
10
11
Description
Reserved.
DAC update rate. Set by user to
update the DAC using Timer1.
Cleared by user to update the DAC
using HCLK (core clock).
DAC clear bit. Set by user to enable
normal DAC operation. Cleared by
user to reset data register of the DAC
to 0.
Reserved. This bit should be left at 0.
Reserved. This bit should be left at 0.
DAC range bits.
Power-down mode. The DAC output is
in three-state.
0 V to DAC
0 V to V
0 V to AV
DD
.
Default Value
0x00
0x00
0x00
0x00
REF
DD
(2.5 V) range.
REF
range.
REF
range.
, and 0 V to AV
REF
(internal
Access
R/W
R/W
R/W
R/W
DD
.
Rev. D | Page 52 of 96
Table 51. DACxDAT Registers
Name
DAC0DAT
DAC1DAT
DAC2DAT
DAC3DAT
Table 52. DAC0DAT MMR Bit Designations
Bit
31:28
27:16
15:0
Using the DACs
The on-chip DAC architecture consists of a resistor string DAC
followed by an output buffer amplifier. The functional equivalent
is shown in Figure 53.
As illustrated in Figure 53, the reference source for each DAC is
user-selectable in software. It can be AV
0-to-AV
V to the voltage at the AV
output transfer function spans from 0 V to the voltage at the
DAC
spans from 0 V to the internal 2.5 V reference, V
The DAC output buffer amplifier features a true, rail-to-rail
output stage implementation. This means that when unloaded,
each output is capable of swinging to within less than 5 mV of
both AV
(when driving a 5 kΩ resistive load to ground) is guaranteed
through the full transfer function, except Code 0 to Code 100,
and, in 0-to-AV
REF
pin. In 0-to-V
DD
DD
mode, the DAC output transfer function spans from 0
and ground. Moreover, the DAC’s linearity specification
DAC
AV
V
Address
0xFFFF0604
0xFFFF060C
0xFFFF0614
0xFFFF061C
REF
REF
DD
DD
Description
Reserved.
12-bit data for DAC0.
Reserved.
mode only, Code 3995 to Code 4095.
REF
Figure 53. DAC Structure
mode, the DAC output transfer function
DD
R
R
R
R
R
pin. In 0-to-DAC
Default Value
0x00000000
0x00000000
0x00000000
0x00000000
DD
, V
REF
REF
, or DAC
REF
mode, the DAC
DAC0
.
Access
R/W
R/W
R/W
R/W
REF
. In