C8051F986-GUR Silicon Labs, C8051F986-GUR Datasheet - Page 320

• Manufacturer Part Number: C8051F986-GUR
• Description: 8-bit Microcontrollers - MCU 8kB 512B RAM 12b ADC
• Manufacturer: Silicon Labs

Specifications of C8051F986-GUR

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

C8051F99x-C8051F98x
27.2. C2 Pin Sharing
The C2 protocol allows the C2 pins to be shared with user functions so that in-system debugging and
Flash programming may be performed. This is possible because C2 communication is typically performed
when the device is in the halt state, where all on-chip peripherals and user software are stalled. In this
halted state, the C2 interface can safely “borrow” the C2CK (RST) and C2D pins. In most applications,
external resistors are required to isolate C2 interface traffic from the user application. A typical isolation
configuration is shown in Figure 27.1.
The configuration in Figure 27.1 assumes the following:
Additional resistors may be necessary depending on the specific application.
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1. The user input (b) cannot change state while the target device is halted.
2. The RST pin on the target device is used as an input only.
Output (c)
RST (a)
Input (b)
Figure 27.1. Typical C2 Pin Sharing
C2 Interface Master
Rev. 1.1
C2CK
C2D
C8051Fxxx