Accessing the hyperframe control words, Specifying the control word, Accessing the hyperframe control words -37 – Altera CPRI v6.0 MegaCore Function User Manual

Page 67

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Accessing the Hyperframe Control Words

When you turn on Enable all control word access in the CPRI v6.0 parameter editor, you can access the

256 control words in a hyperframe through the CPRI v6.0 IP core CPU interface. The

CTRL_INDEX

register

and the

RX_CTRL

register support your application in reading the incoming control words, and the

L1_CONFIG

register,

CTRL_INDEX

register, and

TX_CTRL

register support the application in writing to

outgoing control words.
Register support provides you access to the full control word. Alternatively, in timing-critical applications,

you can access the full control words through the CPRI v6.0 IP core AUX interface or other dedicated

direct interfaces.
Note: Altera recommends that you use the CPU interface to access the hyperframe control words only in

applications that are not timing-critical.

Specifying the Control Word

Figure 3-27: Subchannels in a Hyperframe

Illustrates how the 256 control words in the hyperframe are organized as 64 subchannels of four control

words each. The figure illustratres why the index X of a control word is Ns + 64 + Xs, where Ns is the

subchannel index and Xs is the index of the control word within the subchannel.

Xs == 0123

Ns == 0

0: K28.5

Synchronization and Timing

1

1: HDLC link

65: HDLC

129: HDLC

193: HDLC

2

2: L1 In-band

66: L1 in-band

130: L1 in-band

194: P (20 = 0x14)

3

3: Reserved

67: Reserved

4

4: Ctrl_AxC

...

...

...

...

7

7: Ctrl_AxC

71: Ctrl_AxC

135: Ctrl_AxC

199: Ctrl_AxC

...

14

14: Reserved

15

15: Reserved

79: Reserved

143: Reserved

207: Reserved

16

Vendor-specific

...

19
20

Pointer P --->

20: Ethernet

...

62

62

126

190

254

63

63

127

191

255

The

rx_ctrl_x

and

tx_ctrl_x

fields of the

CTRL_INDEX

register hold the X value of the control word you

want to access through the control and status interface.

UG-01156

2014.08.18

Accessing the Hyperframe Control Words

3-37

Functional Description

Altera Corporation

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