Power-On Self-Test (POST)

Each time you turn on the system, the Power-on Self Test (POST) is initiated. Several items are tested during POST, but is for the most part transparent to the user.

The Power-On Self Test (POST) is a BIOS procedure that boots the system, initializes and diagnoses the system components, and controls the operation of the power-on password option. If POST discovers errors in system operations at power-on, it displays error messages on screen, generates a check point code at port 80h or even halts the system if the error is fatal.

The main components on the main board that must be diagnosed and/or initialized by POST to ensure system functionality are as follows:

Microprocessor with built-in numeric co-processor and cache memory subsystem Direct Memory Access (DMA) controller

Interrupt system

Three programmable timers ROM subsystem

RAM subsystem

CMOS RAM subsystem and real time clock/calendar with battery backup Onboard parallel interface controller

Embedded hard disk interface and one diskette drive interface Keyboard and auxiliary device controllers

1.44M floppy controller I/O ports

One parallel port

One PS/2-compatible mouse port

One PS/2-compatible keyboard port

NOTE: When Post executes a task, it uses a series of preset numbers called check points to be latched at

port 80h, indicating the stages it is currently running. This latch can be read and shown on a debug board.

The following table describes the BIOS common tasks carried out by POST. Each task is denoted by an unique check point number. For other unique check point numbers that are not listed in the table, refer to the corresponding product service guide.

Post Checkpoints List: The list may vary accordingly depending on your BIOS

.

 

Checkpoint

Description

 

 

 

 

 

 

CFh

Test CMOS R/W functionality

 

 

 

 

 

 

C0h

Early chipset initialization:

 

 

 

-Disable shadow RAM

 

 

 

-Disable L2 cache (socket 7 or below)

 

 

 

-Program basic chipset registers

 

 

 

 

 

 

C1h

Detect memory

 

 

 

-Auto-detection of DRAM size, type and ECC.

 

 

 

-Auto-detection of L2 cache (socket 7 or below)

 

 

 

 

 

 

C3h

Expand compressed BIOS code to DRAM

 

 

 

 

 

 

C5h

Call chipset hook to copy BIOS back to E000 & F000 shadow RAM.

 

 

 

 

 

 

01h

Expand the Xgroup codes locating in physical address 1000:0

 

 

 

 

 

 

02h

Reserved

 

 

 

 

 

 

 

 

 

82

Chapter 4

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Acer L310 manual Power-On Self-Test Post, Checkpoint Description

L310 specifications

The Acer L310 is a compact and versatile desktop computer that caters to users seeking a powerful yet space-saving solution for their home or office. Launched as part of Acer's lineup, the L310 is designed to meet the increasing demands of everyday computing, whether it be for work, entertainment, or educational purposes.

One of the main features of the Acer L310 is its efficient design. The sleek chassis of the desktop is not only aesthetically pleasing but also engineered for optimal airflow, which aids in thermal management. This compact form factor makes it easy to integrate into any environment, whether on a desk or a shelf, without taking up excessive space.

Performance-wise, the Acer L310 is equipped with a range of powerful hardware options designed to deliver smooth multitasking and efficient operation. It is often powered by Intel’s processors, offering choices from entry-level to more advanced CPUs, which cater to a wide range of user needs. This enables users to run multiple applications simultaneously, stream videos, and even complete light gaming tasks without a hitch.

The Acer L310 also comes with generous memory configurations, often featuring up to 8GB of RAM or more, allowing for quick data access and improved multitasking capabilities. Furthermore, it offers ample storage options, typically including both HDDs and SSDs, ensuring that users have enough space to store their files, documents, and multimedia. The integration of SSDs can significantly enhance boot times and overall system responsiveness.

In terms of connectivity, the Acer L310 is well-equipped with various ports, including USB 3.0 ports, HDMI and VGA outputs, and audio jacks, enabling users to connect a multitude of peripherals and external devices. The support for both wired and wireless networking allows for flexible internet connectivity, making it suitable for a variety of networking environments.

The L310 also emphasizes energy efficiency with its power-saving technologies. This not only reduces the overall energy consumption but also translates to lower electricity bills over time, making it an environmentally friendly choice for users.

In conclusion, the Acer L310 combines a compact design with powerful performance features, making it an appealing option for anyone in need of a reliable and efficient desktop solution. Its blend of performance, connectivity, and energy efficiency makes it suitable for home, office, or educational use, catering to a wide range of computing needs.