General Z13S Ras Features; Connectivity - IBM z13s Technical Manual

downstream data signals can be spared by using two spare wires on both the upstream and
downstream paths. One of these signals can be used to spare a clock signal line (one
upstream and one downstream). The following improvements were also added in the z13s
servers:
No cascading of memory DIMMs
Independent channel recovery
Double tabs for clock lanes
Separate replay buffer per channel
Hardware driven lane soft error rate (SER) and sparing.

2.5.2 General z13s RAS features

z13s servers have the following RAS features:
z13s servers provide a true N+1 (fully redundant) cooling function for the CPC drawers
and the PCIe drawers by using the blowers. If a blower fails, the second blower increases
the speed of the fans to provide necessary cooling until the failed blower is replaced. The
power supplies for the z13s servers are also based on the N+1 design. The second power
supply can maintain operations and avoid an unplanned outage of the system.
The z Systems processors have improved chip packaging (encapsulated chip connectors)
and use SER hardened latches throughout the design.
z13s servers have N+2 point of load (POL) power conversion. This redundancy protects
the processor from the loss of voltage because of POL failures.
z13s servers have N+2 redundancy on the environmental sensors (ambient temperature,
relative humidity, air density
Enhanced bus structure using integrated time-domain reflectometry (TDR) technology.
z13s servers have these Peripheral Component Interconnect Express (PCIe) service
enhancements:
– Mandatory end-to-end cyclic redundancy check (ECRC)
– Customer operation code separate from maintenance code
– Native PCIe firmware stack running on the integrated firmware processor (IFP) to
manage isolation and recovery
IBM z13s servers continue to deliver robust server designs through exciting new
technologies, hardening both new and classic redundancy.
For more information, see Chapter 9, "Reliability, availability, and serviceability" on page 355.

2.6 Connectivity

Connections to PCIe I/O drawers, I/O drawers, Parallel Sysplex InfiniBand (PSIFB) coupling,
and Integrated Coupling Adapters (ICA) are driven from the CPC drawer fanout cards. These
fanouts are on the front of the CPC drawer.
2
The air density sensor measures air pressure and is used to control blower speed.
2
, and corrosion).
Chapter 2. Central processor complex hardware components
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