IBM z13s, Technical Manual

Page: 124 / 588

96
IBM z13s Technical Guide
Figure 3-11 shows the location of the coprocessor on the chip.
Figure 3-11 Compression and cryptography accelerators on a core in the chip
CP Assist for Cryptographic Function
CPACF accelerates the encrypting and decrypting of SSL/TLS transactions, virtual private
network (VPN)-encrypted data transfers, and data-storing applications that do not require
FIPS
2
140-2 level 4 security. The assist function uses a special instruction set for symmetrical
clear key cryptographic encryption and decryption, and for hash operations. This group of
instructions is known as the
Message-Security Assist
(MSA). For more information about
these instructions, see
z/Architecture Principles of Operation, SA22-7832.
For more information about cryptographic functions on z13s servers, see Chapter 6,
“Cryptography” on page 199.
3.4.6 Decimal floating point accelerator
The DFP accelerator function is present on each of the microprocessors (cores) on the 8-core
chip. Its implementation meets business application requirements for better performance,
precision, and function.
Base 10 arithmetic is used for most business and financial computation. Floating point
computation that is used for work that is typically done in decimal arithmetic involves frequent
data conversions and approximation to represent decimal numbers. This process has made
floating point arithmetic complex and error-prone for programmers who use it for applications
in which the data is typically decimal.
Hardware decimal floating point computational instructions provide the following features:
򐂰 Data formats of 4 bytes, 8 bytes, and 16 bytes
򐂰 An encoded decimal (base 10) representation for data
򐂰 Instructions for running decimal floating point computations
򐂰 An instruction that runs data conversions to and from the decimal floating point
representation
2
Federal Information Processing Standard (FIPS) 140-2 Security Requirements for Cryptographic Modules
Input Buffer
Output
merger
LSU
CoP- store
Output Buffer
Crypto Cipher
(DES and AES)
Crypto Hash
(SHA)
IDU
FXU
CO
P
VFU
RU
IFB
ICM XU
L2I L2D
PC
LSU
IS
U
UTF
Conversion
Compression
CMPSC
millicode
To/from
ICM