C8051F39x/37x
33. C2 Interface
C8051F39x/37x devices include an on-chip Silicon Labs 2-Wire (C2) debug interface to allow Flash pro-
gramming and in-system debugging with the production part installed in the end application. The C2 inter-
face uses a clock signal (C2CK) and a bi-directional C2 data signal (C2D) to transfer information between
the device and a host system. See the C2 Interface Specification for details on the C2 protocol.
33.1. C2 Interface Registers
The following describes the C2 registers necessary to perform Flash programming through the C2 inter-
face. All C2 registers are accessed through the C2 interface as described in the C2 Interface Specification.
C2 Register Definition 33.1. C2ADD: C2 Address
Bit
7
6
5
4
3
2
1
0
Name
C2ADD[7:0]
Type
R/W
Reset
0
0
0
0
0
0
0
0
Bit Name
Function
7:0 C2ADD[7:0] C2 Address.
The C2ADD register is accessed via the C2 interface to select the target Data register
for C2 Data Read and Data Write commands.
Address
0x00
0x01
0x02
0xB4
Description
Selects the Device ID register for Data Read instructions
Selects the Revision ID register for Data Read instructions
Selects the C2 Flash Programming Control register for Data
Read/Write instructions
Selects the C2 Flash Programming Data register for Data Read/
Write instructions
Preliminary Rev. 0.71
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