ADUC7121 Analog Devices, ADUC7121 Datasheet - Page 49

• Manufacturer Part Number: ADUC7121
• Description: Precision Analog Microcontroller, 12-Bit Analog I/O, ARM7TDMI MCU
• Manufacturer: Analog Devices

Specifications of ADUC7121

• Mcu Core: ARM7 TDMI
• Mcu Speed (mips): 40
• Sram (bytes): 8192Bytes
• Gpio Pins: 32
• Adc # Channels: 9

MMRs and Keys
To prevent accidental programming, a certain sequence must be
followed when writing in the PLLCON and POWCON registers
(see Table 67).
PLLKEYx Registers
Name:
Address:
Default value:
Access:
Name:
Address:
Default value:
Access:
PLLCON Register
Name:
Address:
Default value:
Access:
Table 65. PLLCON MMR Bit Designations
Bit
7:6
5
4:2
1:0
Value
00
01
10
11
Name
OSEL
MDCLK
PLLKEY1
0xFFFF0410
0x0000
Write only
PLLKEY2
0xFFFF0418
0x0000
Write only
PLLCON
0xFFFF0414
0x21
Read and write
Description
Reserved.
32 kHz PLL input selection.
Set by the user to use the internal
32 kHz oscillator.
Set by default.
Cleared by the user to use the external
32 kHz crystal.
Reserved.
Clocking modes.
Reserved.
PLL. Default configuration.
Reserved.
External clock on the
P1.4/PWM1/ECLK/XCLK/PLAI[8] pin.
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POWKEYx Registers
Name:
Address:
Default value:
Access:
Name:
Address:
Default value:
Access:
POWCON Register
Name:
Address:
Default value:
Access:
Table 66. POWCON MMR Bit Designations
Bit
7
6:4
3
2:0
Table 67. PLLCON and POWCON Write Sequence
PLLCON
PLLKEY1 = 0xAA
PLLCON = 0x01
PLLKEY2 = 0x55
Value
000
001
010
011
100
Others
000
001
010
011
100
101
110
111
Name
PC
RSVD
CD
POWKEY1
0xFFFF0404
0x0000
Write only
POWKEY2
0xFFFF040C
0x0000
Write only
POWCON
0xFFFF0408
0x0003
Read and write
Description
Reserved.
Operating modes.
Active mode.
Pause mode.
Nap mode.
Sleep mode. IRQ0 to IRQ3 and Timer2
can wake up the ADuC7121.
Stop mode.
Reserved.
Reserved.
CPU clock divider bits.
41.779200 MHz.
20.889600 MHz.
10.444800 MHz.
5.222400 MHz.
2.611200 MHz.
1.305600 MHz.
654.800 kHz.
326.400 kHz.
POWCON
POWKEY1 = 0x01
POWCON = user value
POWKEY2 = 0xF4
ADuC7121