Chapter 5 Registers - NEC UPD98413 User Manual

µ
The PD98413 has registers that can be accessed via the CPU interface. These registers are used to specify
commands, set operation modes, and analyze interrupt causes.
[Caution]
The data bit string of the SONET/SDH frame is sequentially transmitted from the MSB when it is transmitted from
the line interface (circuit side). In this document, the MSB is always shown on the left side in tables and figures.
Note that each bit in the overhead byte (OH byte) of the SONET/SDH frame is described in the following two ways:
Description <1> Bits 1 to 8
This description is mainly used to indicate the bit string of the overhead byte in the SONET/SDH frame in the
order in which the bits are output from the line interface.
Description <2> D31 to D0 bits
This description is mainly used to indicate the bits in an internal register of the
correspond to the AD31 to AD0 pins of the external CPU interface.
In this document, the following two descriptions are also used to indicate the same overhead byte in the
SDH/SONET frame.
Description <1>
Description <2>

CHAPTER 5 REGISTERS

CHAPTER 5 REGISTERS
<1> Indicating bits in overhead byte
Bit 1 Bit 2 Bit 3 Bit 4
1 2 3 4
D31 D30 D29 D28
D23 D22 D21 D20
D15 D14 D13 D12
D7 D6 D5 D4
<2> Indicating bits in internal register
(D31 is input/output to/from data bus AD31 of the CPU interface.)
H1 H1 H1
1st H1 2nd H1 3rd H1
H1#1 H1#2 H1#3
PRELIMINARY
Bit 5 Bit 6 Bit 7 Bit 8
5
D27 D26 D25 D24
D19 D18 D17 D16
D11 D10 D9 D8
D3 D2 D1 D0
H1 H1
47th H1 48th H1 1st H1
H1#47 H1#48
µ
PD98413. The bits
Transmission
sequence
H2 H2
2nd H1
H1#1 H1#2
NEC confidential and Proprietary
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