HDLC CONTROLLERS
S3C4510B
HDLC PREAMBLE CONSTANT REGISTER (HPRMB)
The HPRMB register is used to meet the DPLL requirements for phase-locking. The preamble pattern is
transmitted as many Tx preamble length bit values in HMODE[10:8] when the Tx preamble bit (TxPRMB) is '1',
and then the Tx preamble bit is cleared automatically. The opening flag follows this preamble pattern, and the
data will be transmitted.
Table 8-15. HPRMBA and HPRMBB Register
Registers
HPRMBA
HPRMBB
Offset
0x7020
0x8020
R/W
R/W
R/W
Description
Reset Value
0x00000000
0x00000000
HDLC Preamble Constant Register
HDLC Preamble Constant Register
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9
8 7 6 5 4 3 2 1 0
Preamble Pattern
[7:0] Preamble Pattern
Figure 8-22. HDLC Preamble Constant Register
The reference for the preamble pattern of each data mode is as follows:
Table 8-16. Preamble Reference Pattern
Data Mode
NRZ
Preamble Pattern
AA
00
NRZI
FM0
FF
00
FM1
MANCHESTER
AA
8-46
SAMSUNG [ SAMSUNG ]
