C8051F320-TB Silicon Laboratories Inc, C8051F320-TB Datasheet - Page 247

• Manufacturer Part Number: C8051F320-TB
• Description: BOARD PROTOTYPING W/C8051F320
• Manufacturer: Silicon Laboratories Inc
• Type: MCUr

Specifications of C8051F320-TB

• Contents: Board
• Processor To Be Evaluated: C8051F320/F321
• Interface Type: USB
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• For Use With/related Products: C8051F320
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

21.2. C2 Pin Sharing
The C2 protocol allows the C2 pins to be shared with user functions so that in-system debugging and
Flash programming functions 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 (P3.0) pins. In most
applications, external resistors are required to isolate C2 interface traffic from the user application. A typi-
cal isolation configuration is shown in Figure 21.1.
The configuration in Figure 21.1 assumes the following:
Additional resistors may be necessary depending on the specific application.
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.
/Reset (a)
Output (c)
Input (b)
Figure 21.1. Typical C2 Pin Sharing
C2 Interface Master
Rev. 1.4
C2CK
C2D
C8051Fxxx
C8051F320/1
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