EM77F900 Datasheet, PDF (67/136 Pages) ELAN Microelectronics Corp – USB HUB+BB Controller

EM77F900
USB HUB+BB Controller
8.2.15 Input Synchronizer
Handling asynchronous inputs to the BB.
Asynchronous
Input
S ^SET Q
R CLR Q
S ^SET Q
R CLR Q
Synchronized
Input
CLK
8.3 Register Description
The registers in the BB are divided into three groups:
Read-only registers which are mainly status registers.
Write-only registers which are mainly control registers.
Read and write registers.
In case of a RST pulse, all registers are set to their default value.
8.3.1 Bit Length Register (BLR)
This register is both a read and a write register.
It determines the length of the bit in terms of clock cycles.
The bit length will be (BLR+6) clocks, since the minimum length of a bit is 6 clocks.
Default Value: 00 (0+6=6).
8.3.2 Preamble Low Register (PRE-L)
This register is a write-only register.
This register contains the 8 least significant bits of the PREAMBLE.
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1
PRE-L PR-7 PR-6 PR-5 PR-4 PR-3 PR-2 PR-1
Bit 0
PR-0
Default Value: 0xEB.
8.3.3 Preamble High Register (PRE-H)
This register is a write-only register.
This register contains the 8 most significant bits of the PREAMBLE.
Name
PRE-H
Bit 7
PR-15
Bit 6
PR-14
Bit 5
PR-13
Bit 4
PR-12
Bit 3
PR-11
Bit 2
PR-10
Bit 1
PR-9
Bit 0
PR-8
Default Value: 0xFF.
Product Specification (V1.0) 07.31.2007
(This specification is subject to change without further notice)
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