
IBM3206K0424
Preliminary
IBM Processor for Network Resources
pnr25.chapt06.01
August 14, 2000
GPPINT Architecture
Page 525 of 676
Sonet Framer Core (FRAMR Chiplet Address Mapping)
GPPINT Architecture
Overview
The General Purpose Processor INTerface (GPPINT) provides direct access to registers located in the 
GPPINT module; it provides delayed access to registers and counters located in the GppHandler modules of 
the various chiplets of the SONET core. GPPINT controls the handshaking with the external microprocessor 
as well as the handshaking with the GppHandlers at the asynchronous chiplet interfaces. Address decoding 
is done to the chiplet level in GPPINT. In addition, addresses are decoded to the register level for the local 
GPPINT registers.
Reset Register
Each chiplet is controlled by one reset bit. At power-on, all reset bits are active and the chiplets are disabled. 
They can be released by the General Purpose Processor (GPP) only after all global configuration parameters 
have been set and the clocks to the chiplets have been established. In addition, there are reset bits for the 
chiplets that do not have their own GppHandler.
Interrupt Registers
The interrupt register is used as a pointer to the chiplet interrupt registers with pending requests: the clock 
status error register, and the handshaking error register. An active bit of the interrupt register is reset by 
removing the cause for the request in the corresponding chiplet or by masking the active IRQ bit(s) in the 
chiplet; therefore, the interrupt registers (including the pointer) are read only. All interrupt and pointer regis-
ters have a corresponding MASK register (R/W). Every unmasked, active interrupt bit causes an active 
pointer bit. Every unmasked, active pointer bit causes activation of the interrupt signal to the microprocessor. 
FRAMR Chiplet Address Mapping 
Chiplet Name
Short Name
Chiplet Base Address
Chiplet Address Range
Number of Bytes
Reserved
X
’
000
’
X
’
000 - 0FF
’
256
ACH_Tx
HT
X
’
100
’
X
’
100 - 1FF
’
256
ACH_Rx
HR
X
’
200
’
X
’
200 - 2FF
’
256
Reserved
X
’
300
’
X
’
300 - 3FF
’
256
OFP_Tx
OT
X
’
400
’
X
’
400 - 7FF
’
1024
OFP_Rx
OR
X
’
800
’
X
’
800 - BFF
’
1024
GPPINT
GP
X
’
C00
’
X
’
C00 - CFF
’
256
Reserved
X
’
D00
’
X
’
D00 - FFF
’
768