ADUC7026_15 Datasheet, PDF (69/104 Pages) Analog Devices – Precision Analog Microcontroller, 12-Bit Analog I/O, ARM7TDMI MCU

Data Sheet
Table 83. GPIO Drive Strength Control Bits Descriptions
Control Bits Value Description
00
Medium drive strength.
01
Low drive strength.
1x
High drive strength.
3.6
3.4
3.2
3.0
2.8
2.6
2.4
HIGH DRIVE STRENGTH
2.2
MEDIUM DRIVE STRENGTH
LOW DRIVE STRENGTH
2.0
–24 –18 –12 –6
0
6
12
18 24
LOAD CURRENT (mA)
Figure 73. Programmable Strength for High Level
(Typical Values)
0.5
0.4
0.3
0.2
0.1
0
–0.1
–0.2
–0.3
–0.4
–24 –18 –12 –6
HIGH DRIVE STRENGTH
MEDIUM DRIVE STRENGTH
LOW DRIVE STRENGTH
0
6
12
18 24
LOAD CURRENT (mA)
Figure 74. Programmable Strength for Low Level
(Typical Values)
The drive strength bits can be written to one time only after
reset. More writing to related bits has no effect on changing
drive strength. The GPIO drive strength and pull-up disable is
not always adjustable for the GPIO port. Some control bits
cannot be changed (see Table 84).
ADuC7019/20/21/22/24/25/26/27/28/29
Table 84. GPxPAR Control Bits Access Descriptions
Bit
GP0PAR
GP1PAR
31
Reserved
Reserved
30 to 29
R/W
R/W
28
R/W
R/W
27
Reserved
Reserved
26 to 25
R/W
R/W
24
R/W
R/W
23
Reserved
Reserved
22 to 21
R/W
R (b00)
20
R/W
R/W
19
Reserved
Reserved
18 to 17
R (b00)
R (b00)
16
R/W
R/W
15
Reserved
Reserved
14 to 13
R (b00)
R (b00)
12
R/W
R/W
11
Reserved
Reserved
10 to 9
R (b00)
R (b00)
8
R/W
R/W
7
Reserved
Reserved
6 to 5
R (b00)
R (b00)
4
R/W
R/W
3
Reserved
Reserved
2 to 1
R (b00)
R (b00)
0
R/W
R/W
Rev. F | Page 69 of 104