C8051F575-IMR Silicon Labs, C8051F575-IMR Datasheet - Page 167

• Manufacturer Part Number: C8051F575-IMR
• Description: 8-bit Microcontrollers - MCU 50 MIPS 16 kB 2 kB SPI UART I2C
• Manufacturer: Silicon Labs

Specifications of C8051F575-IMR

• Rohs: yes
• Core: 8051
• Processor Series: C8051
• Data Bus Width: 8 bit

19. Port Input/Output
Digital and analog resources are available through 33 (C8051F568-9 and ‘F570-5), 25 (C8051F550-7) or
18 (C8051F550-7) I/O pins. Port pins P0.0-P4.0 on the C8051F568-9 and ‘F570-5, port pins P0.0-P3.0 on
theC8051F560-7, and port pins P0.0-P2.1 on the C8051F550-7 can be defined as general-purpose I/O
(GPIO), assigned to one of the internal digital resources, or assigned to an analog function as shown in
Figure 19.3. Port pin P4.0 on the C8051F568-9 and ‘F570-5 can be used as GPIO and is shared with the
C2 Interface Data signal (C2D). Similarly, port pin P3.0 is shared with C2D on the C8051F560-7 and port
pin P2.1 on the C8051F550-7. The designer has complete control over which functions are assigned, lim-
ited only by the number of physical I/O pins. This resource assignment flexibility is achieved through the
use of a Priority Crossbar Decoder. Note that the state of a Port I/O pin can always be read in the corre-
sponding Port latch, regardless of the Crossbar settings.
The Crossbar assigns the selected internal digital resources to the I/O pins based on the Priority Decoder
(Figure 19.3 and Figure 19.4). The registers XBR0, XBR1, XBR2 are defined in SFR Definition 19.1 and
SFR Definition 19.2 and are used to select internal digital functions.
The Port I/O cells are configured as either push-pull or open-drain in the Port Output Mode registers
(PnMDOUT, where n = 0,1). Complete Electrical Specifications for Port I/O are given in Table 5.3 on
page 40.
Highest
Lowest
Priority
Priority
Latches
Port
/SYSCLK
SMBus0
UART0
T0, T1,
/INT0,
CAN0
PCA0
/INT1
SPI0
LIN0
CP0
CP1
P0
P1
P2
P3
P4
(Px.0-Px.7)
33
Figure 19.1. Port I/O Functional Block Diagram
2
2
4
2
2
2
7
4
2
XBR2, PnSKIP
XBR0, XBR1,
Crossbar
Decoder
Priority
Rev. 1.1
Digital
8
8
8
8
8
C8051F55x/56x/57x
PnDMIN Registers
PnMDOUT,
Cells
Cells
Cells
Cells
Cell
I/O
I/O
I/O
I/O
I/O
P0
P1
P2
P3
P4
PnMATCH
Registers
PnMASK
External
Pins
P0.0
P0.7
P1.0
P1.7
P2.0
P2.7
P3.0
P3.7
P4.0
Highest
Priority
Lowest
Priority
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