Sony AR-B1570 manual Real-Time Clock and Non-Volatile RAM, Timer, Address Description

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AR-B1570 Users Guide

2.4.2 Real-Time Clock and Non-Volatile RAM

The AR-B1570 contains a real-time clock compartment that maintains the date and time in addition to storing configuration information about the computer system. It contains 14 bytes of clock and control registers and 114 bytes of general purpose RAM. Because of the use of CMOS technology, it consumes very little power and can be maintained for long periods of time using an internal Lithium battery. The contents of each byte in the CMOS RAM are listed as follows:

Address

Description

00

Seconds

01

Second alarm

02

Minutes

03

Minute alarm

04

Hours

05

Hour alarm

06

Day of week

07

Date of month

08

Month

09

Year

0A

Status register A

0B

Status register B

0C

Status register C

0D

Status register D

0E

Diagnostic status byte

0F

Shutdown status byte

10

Diskette drive type byte, drive A and B

11

Fixed disk type byte, drive C

12

Fixed disk type byte, drive D

13

Reserved

14

Equipment byte

15

Low base memory byte

16

High base memory byte

17

Low expansion memory byte

18

High expansion memory byte

19-2D

Reserved

2E-2F

2-byte CMOS checksum

30

Low actual expansion memory byte

31

High actual expansion memory byte

32

Date century byte

33

Information flags (set during power on)

34-7F

Reserved for system BIOS

Real-Time Clock & Non-Volatile RAM

2.4.3 Timer

The AR-B1570 provides three programmable timers, each with a timing frequency of 1.19 MHz.

Timer 0 The output of this timer is tied to interrupt request 0. (IRQ 0)

Timer 1 This timer is used to trigger memory refresh cycles.

Timer 2 This timer provides the speaker tone.

Application programs can load different counts into this timer to generate various sound frequencies.

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Contents Industrial Grade CPU Board AR-B1570 User’s Guide Save & Exit Setup Exit Without Saving Preface Organization Static Electricity PrecautionsCPU NS Geode GX1 BGA 1SPECIFICATIONOverview Packing ListCPU NS Geode GX1 FeaturesAward Bios DMA Controller System ControllerMicroprocessor Interrupt Controller Keyboard ControllerInterrupt Controller Port Address Map 1 I/O Port Address MapHex Range Device SSDReal-Time Clock & Non-Volatile RAM TimerReal-Time Clock and Non-Volatile RAM Address DescriptionSerial Port Divisor Latch LS, MS Modem Control Register MCRLine Status Register LSR Modem Status Register MSRData Swapper Parallel PortRegister Address Printer Interface LogicBit’s Definition Printer Control Latch & Printer Control SwapperExternal System Location Setting UP the SystemSystem Setting OverviewPin Signal Hard Disk IDE ConnectorPin Hard Disk IDE Connector CN8 Pin Hard Disk IDE Connector CN7FDD Pin Assignment FDD Port Connector CN3Hard Disk IDE1 Connector PS-ON Header CN9 Ethernet RJ-45 Connector LAN14 PS/2 KB/Mouse Connector CN4 & PS1 Reset Header J7P4 CRT Connector Power Connector PWR2CRT Connector P4 LCD Panel Display Connector LCD1Pin Description USB ConnectorUSB1LED Header J8 LCD Display Pin AssignmentPin PC/104 Connector Bus C & D PC104 13 PC104 ConnectorPin PC/104 Connector Bus a & B PC104 15 IR. Header J1 Parallel Port Connector CN216 Ext. Battery CN1 Battery Jumper JP2RS-485 Terminator Select J2 RS-232 Connector Pin Assignment18 COM1, COM2 CN5, CN6 RS-232/RS-485 Select for COM1 P2 & P320 D.O.C. Memory Address Select JP1 Touch Screen Connector J3 & J4ATX Power External Bottom Connector J6 Utility Diskette InstallationDriver Installation Disk Watchdog TimerWatchdog Block Diagram IRQ Watchdog Timer SettingWatchdog Timer Trigger Bios Setup Main Menu Bios ConsoleBios Setup Overview Floppy Setup Standard Cmos SetupDate & Time Setup Hard Disk SetupMono Halt OnEGA/VGA Bios Features Setup Memory Parity Check Typematic Rate SettingTypematic Delay Msec Video Bios ShadowSdram CAS latency Time Chipset Features SetupBit I/O Cycle Recovery Time Chipset Features SetupLoad Setup Defaults PNP/PCI ConfigurationLoad Default Setting Load Bios DefaultsIntegrated Peripherals IDE HDD Auto Detection Password SettingBios Exit