PM8621 datasheet(146/184 Pages) PMC

146 / 184 page

NSE-8G™ Standard Product Data Sheet

Preliminary

Proprietary and Confidential to PMC-Sierra, Inc., and for its Customers’ Internal Use

145

Document ID: PMC-2010850, Issue 1

Example: Suppose one wishes to change the cross bar to map DIN[10][12:0] to DOUT[6][12:0]

for just the 4097th byte of the frame and wishes to keep all other mappings of the 4097th byte the

same.

Steps:

1. CPU writes 0x8a061000 to the DCB Access Mode register (i.e., WRB=1, ACCMDE=0,

PORTCFG[4:0]=0x0A, PORTADDR[4:0]=0x06, WORDADDR[13:0]=0x1000).

° Causes MUX B to switch in PORTCFG at port 6.

° Causes MUX C to switch in MUX B.

° Triggers a read from offline memory connection page at location 0x1000.

2. Wait four SYSCLK cycles.

3. Writes 0x0a061000 to the DCB Access Mode register (i.e., WRB=0, ACCMDE=0,

PORTCFG[4:0]=0x0A, PORTADDR[4:0]=0x06, WORDADDR[13:0]=0x1000).

° Causes MUX B to switch in PORTCFG at port 6.

° Causes MUX C to switch in MUX B.

° Triggers a write from register D to offline connection memory page at location 0x1000.

4. Wait four SYSCLK cycles before returning to step 1 to perform another mapping change.

12.6.2 Configuring the DCB using Word transfer mode:

In word transfer mode, the microprocessor updates the entire word of offline connection memory

page. The steps to perform a word transfer is shown in the following example:

Example: Suppose one wishes to change the entire cross bar mapping from DIN to DOUT for just

the 4097th byte of the frame.

Steps:

1. CPU writes new mapping to the Configuration 31-30 Port register.

2. CPU writes new mapping to the Configuration 29-24 Port register.

3. CPU writes new mapping to the Configuration 23-18 Port register.

4. CPU writes new mapping to the Configuration 17-12 Port register.

5. CPU writes new mapping to the Configuration 11-6 Port register.

6. CPU writes new mapping to the Configuration 5-0 Port register .

7. CPU write 0x40001000 to the DCB Access Mode register.

° Causes Mux C to switch in WORDCFG.

PM8621 Datasheet(PDF) 146 Page - PMC-Sierra, Inc