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GLYPH<SM590000> Dedicated Co-Processor (CoP): The dedicated coprocessor is responsible for data compression and encryption functions for each core. 

## 2.3.3 PU characterization 

GLYPH<SM590000> Core pervasive unit (PC) for instrumentation and error collection. 

GLYPH<SM590000> Modulo arithmetic (MA) unit: Support for Elliptic Curve Cryptography: 

– Vector and Floating point Units (VFU): 

GLYPH<129> BFU: Binary floating point unit 

GLYPH<129> DFU: Decimal floating point unit 

GLYPH<129> DFx: Decimal fixed-point unit 

GLYPH<129> FPd: Floating point divide unit 

GLYPH<129> VXx: Vector fixed-point unit 

GLYPH<129> VXs: Vector string unit 

GLYPH<129> VXp: Vector permute unit 

GLYPH<129> VXm: Vector multiply unit 

– L2I/L2D – Level 2 instruction/data cache 

The PUs are characterized for client use. The characterized PUs can be used in general to run supported operating systems, such as z/OS, z/VM, and Linux on Z. They also can run specific workloads, such as Java, XML services, IPSec, and some Db2 workloads, or clustering functions, such as the Coupling Facility Control Code (CFCC). 

The maximum number of characterizable PUs depends on the z15 CPC drawer feature code. Some PUs are characterized for system use; some are characterized for client workload use. 

By default, one spare PU is available to assume the function of a failed PU. The maximum number of PUs that can be characterized for client use are listed in Table 2-3. 

<img src='content_image/975085.jpg'>

The rule for the CP to zIIP purchase ratio is that for every CP purchased, up to two zIIPs can be purchased. Java and XML workloads can run on zIIPs. 

However, an LPAR definition can go beyond the 1:2 ratio. For example, a maximum of four physical zIIPs can be installed on a system with two physical CPs. 

Converting a PU from one type to any other type is possible by using the Dynamic Processor Unit Reassignment process. These conversions occur concurrently with the system operation. 

Note:  The addition of ICFs, IFLs, zIIPs, and SAP to the z15 does not change the system capacity setting or its million service units (MSU) rating. 

