Difference between revisions of "RTC"

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(→‎RTC Registers)
 
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Real Time Clock (RTC)
 +
 
== PC compatible RTC chip ==
 
== PC compatible RTC chip ==
 
=== Usage in CPCs ===
 
=== Usage in CPCs ===
  
 
Usage in [[SYMBiFACE II:Realtime clock]]:
 
Usage in [[SYMBiFACE II:Realtime clock]]:
−
   Uses a Dallas DS1287A RTC chip, mapped to ports:
+
   Uses a Dallas DS12887A RTC chip, mapped to ports:
−
   FD14h SYMBiFACE II Real Time Clock - DS1287A RTC Data  (R/W)
+
   FD14h SYMBiFACE II Real Time Clock - DS12887A RTC Data  (R/W)
−
   FD15h SYMBiFACE II Real Time Clock - DS1287A RTC Index (W)
+
   FD15h SYMBiFACE II Real Time Clock - DS12887A RTC Index (W)
−
  RAM at [32h] is "attempted" to be used as century.
+
 
 
----
 
----
  
 
Usage in [[Dk'tronics Real Time Clock]]:
 
Usage in [[Dk'tronics Real Time Clock]]:
−
   Uses a HD146818 chip.
+
   Uses a Z80 PIO chip to control the HD146818 RTC chip via port A. Do not use Port A as this will affect the RTC operation.
−
   Details on I/O addresses are unknown.
+
   FBE0h  Dk'tronics Real Time Clock - Z80 PIO Port A Data (HD146818P RTC Data bus)
−
   Unknown if century is supported.
+
  FBE1h  Dk'tronics Real Time Clock - Z80 PIO Port B Data, used for external control (General Purpose 8bit I/O Port)
 +
  FBE2h  Dk'tronics Real Time Clock - Z80 PIO Port A Control
 +
  FBE3h  Dk'tronics Real Time Clock - Z80 PIO Port B Control
 +
  FBE8h  Dk'tronics Real Time Clock - Control port for RTC chip (4bit latch) '''(details unknown)'''
 +
   Port B is connected directly to a standard 9-way connector on the left of the interface.
  
 
----
 
----
  
 
Usage in [[Aleste 520EX - I/O Ports]]:
 
Usage in [[Aleste 520EX - I/O Ports]]:
−
   Uses a russian KR512WI1 chip (which is, according to the Aleste's  
+
   Uses a russian KR512WI1 chip (which is, according to the Aleste's Manual) compatible to western MC146818 chips.  
−
  Manual) compatible to western MC146818 chips.  
+
 
   Connects to a 32.768kHz crystal.
 
   Connects to a 32.768kHz crystal.
 
   Connects to the PPI:
 
   Connects to the PPI:
Line 25: Line 30:
 
     PPI Port C.Bit1  = Index Access (0=No, 1=Access)
 
     PPI Port C.Bit1  = Index Access (0=No, 1=Access)
 
     PPI Port C.Bit2  = Data Access  (0=No, 1=Access)
 
     PPI Port C.Bit2  = Data Access  (0=No, 1=Access)
−
   In the Aleste's Ext Port, the RTC must be enabled, and PSG and
+
   In the Aleste's Ext Port, the RTC must be enabled, and PSG and 8253 must be disabled.
−
  8253 must be disabled.
+
−
  Unknown if century is supported.
+
  
 
=== RTC Registers ===
 
=== RTC Registers ===
  
−
  00h  Second      (00..59) ;\
+
Registers 00H-09H in BCD mode:
−
  01h  Alarm second (00..59) ; these ten registers can be BCD or Binary
+
 
−
  02h  Minute      (00..59) ; (see Control B, Bit2=DM)
+
{| class="wikitable" style="text-align:center;"
−
  03h  Alarm minute (00..59) ;
+
|-
−
  04h  Hour        (00..23) ;  ;\in 24hour mode:
+
! rowspan="2" | Register !! colspan="8" | Bit Position !! rowspan="2" | Function !! rowspan="2" | Range
−
  05h  Alarm hour  (00..23) ;  ;/bit7=PM
+
|-
−
  06h  Day of week  (01..07) ;
+
! 7 || 6 || 5 || 4 || 3 || 2 || 1 || 0
−
  07h  Day         (01..31) ;
+
|-
−
  08h  Month       (01..12) ;
+
| 00H || 0 || colspan="3" | 10 Seconds || colspan="4" | Seconds || Seconds || 00–59
−
  09h  Year         (00..99) ;/
+
|-
 +
| 01H || 0 || colspan="3" | 10 Seconds || colspan="4" | Seconds || Seconds Alarm || 00–59
 +
|-
 +
| 02H || 0 || colspan="3" | 10 Minutes || colspan="4" | Minutes || Minutes || 00–59
 +
|-
 +
| 03H || 0 || colspan="3" | 10 Minutes || colspan="4" | Minutes || Minutes Alarm || 00–59
 +
|-
 +
| rowspan="2" | 04H || AM/PM || rowspan="2" | 0 || 0 || 10 Hours || colspan="4" | Hours || rowspan="2" | Hours || 1–12 +AM/PM
 +
|-
 +
| 0 || colspan="2" | 10 Hours || colspan="4" | Hours || 00–23
 +
|-
 +
| rowspan="2" | 05H || AM/PM || rowspan="2" | 0 || 0 || 10 Hours || colspan="4" | Hours || rowspan="2" | Hours Alarm || 1–12 +AM/PM
 +
|-
 +
| 0 || colspan="2" | 10 Hours || colspan="4" | Hours || 00–23
 +
|-
 +
| 06H || 0 || 0 || 0 || 0 || 0 || colspan="3" | Day || Day || 01–07
 +
|-
 +
| 07H || 0 || 0 || colspan="2" | 10 Date || colspan="4" | Date || Date || 01–31
 +
|-
 +
| 08H || 0 || 0 || 0 || 10 Months || colspan="4" | Month || Month || 01–12
 +
|-
 +
| 09H || colspan="4" | 10 Years || colspan="4" | Year || Year || 00–99
 +
|}
 +
 
 +
Registers 00H-09H in binary mode:
 +
 
 +
{| class="wikitable" style="text-align:center;"
 +
|-
 +
! rowspan="2" | Register !! colspan="8" | Bit Position !! rowspan="2" | Function !! rowspan="2" | Range
 +
|-
 +
! 7 || 6 || 5 || 4 || 3 || 2 || 1 || 0
 +
|-
 +
| 00H || 0 || 0 || colspan="6" | Seconds || Seconds || 00–3B
 +
|-
 +
| 01H || 0 || 0 || colspan="6" | Seconds || Seconds Alarm || 00–3B
 +
|-
 +
| 02H || 0 || 0 || colspan="6" | Minutes || Minutes || 00–3B
 +
|-
 +
| 03H || 0 || 0 || colspan="6" | Minutes || Minutes Alarm || 00–3B
 +
|-
 +
| rowspan="2" | 04H || AM/PM || rowspan="2" | 0 || rowspan="2" | 0 || 0 || colspan="4" | Hours || rowspan="2" | Hours || 01–0C +AM/PM
 +
|-
 +
| 0 || colspan="5" | Hours || 00–17
 +
|-
 +
| rowspan="2" | 05H || AM/PM || rowspan="2" | 0 || rowspan="2" | 0 || 0 || colspan="4" | Hours || rowspan="2" | Hours Alarm || 01–0C +AM/PM
 +
|-
 +
| 0 || colspan="5" | Hours || 00–17
 +
|-
 +
| 06H || 0 || 0 || 0 || 0 || 0 || colspan="3" | Day || Day || 01–07
 +
|-
 +
| 07H || 0 || 0 || 0 || colspan="5" | Date || Date || 01–1F
 +
|-
 +
| 08H || 0 || 0 || 0 || 0 || colspan="4" | Month || Month || 01–0C
 +
|-
 +
| 09H || 0 || colspan="7" | Year || Year || 00–63
 +
|}
 +
 
 +
Control registers:
 
   0Ah  Control A
 
   0Ah  Control A
 
         7  UIP Update in Progress (0=Stable in next 244us, 1=Time changes) (R)
 
         7  UIP Update in Progress (0=Stable in next 244us, 1=Time changes) (R)
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         7  VRT  Valid RAM and Time (1=Okay, 0=Battery Low)              (R)
 
         7  VRT  Valid RAM and Time (1=Okay, 0=Battery Low)              (R)
 
         6-0 0    Reserved (zero)
 
         6-0 0    Reserved (zero)
−
  0Eh..3Fh battery backed RAM (DS1287A, and other/newer chips)
 
−
  40h..7Fh battery backed RAM (DS12887A, newer chip variants only)
 
−
  80h..FFh reserved
 
−
  32h      battery backed RAM (commonly used as Century) (19..99) (see notes)
 
−
 
−
=== Century Notes ===
 
  
−
The DS12887A RTC chip used in the SYMBiFACE II does not have a century register. Whether the Aleste and Dk'tronics do have this register is unknown.
+
Non-Volatile RAM:
 +
  0Eh..3Fh battery backed RAM (HD146818, DS1287A, DS12887A and other chips)
 +
  40h..7Fh battery backed RAM (only on DS12887A and newer chip variants)
  
 
== Other chips ==
 
== Other chips ==
Line 78: Line 134:
 
* [[Nova]] (M48T35Y-70MH1F chip)
 
* [[Nova]] (M48T35Y-70MH1F chip)
  
 +
[[Category:Peripherals]]
 
[[Category:Datasheet]]
 
[[Category:Datasheet]]

Latest revision as of 11:33, 4 April 2025

Real Time Clock (RTC)

PC compatible RTC chip

Usage in CPCs

Usage in SYMBiFACE II:Realtime clock: 

 Uses a Dallas DS12887A RTC chip, mapped to ports:
 FD14h SYMBiFACE II Real Time Clock - DS12887A RTC Data  (R/W)
 FD15h SYMBiFACE II Real Time Clock - DS12887A RTC Index (W)

Usage in Dk'tronics Real Time Clock: 

 Uses a Z80 PIO chip to control the HD146818 RTC chip via port A. Do not use Port A as this will affect the RTC operation.
 FBE0h  Dk'tronics Real Time Clock - Z80 PIO Port A Data (HD146818P RTC Data bus)
 FBE1h  Dk'tronics Real Time Clock - Z80 PIO Port B Data, used for external control (General Purpose 8bit I/O Port)
 FBE2h  Dk'tronics Real Time Clock - Z80 PIO Port A Control
 FBE3h  Dk'tronics Real Time Clock - Z80 PIO Port B Control
 FBE8h  Dk'tronics Real Time Clock - Control port for RTC chip (4bit latch) (details unknown)
 Port B is connected directly to a standard 9-way connector on the left of the interface.

Usage in Aleste 520EX - I/O Ports: 

 Uses a russian KR512WI1 chip (which is, according to the Aleste's Manual) compatible to western MC146818 chips. 
 Connects to a 32.768kHz crystal.
 Connects to the PPI:
   PPI Port A.Bit0-7 = Data bus
   PPI Port C.Bit0   = Read/Write   (0=Write, 1=Read)
   PPI Port C.Bit1   = Index Access (0=No, 1=Access)
   PPI Port C.Bit2   = Data Access  (0=No, 1=Access)
 In the Aleste's Ext Port, the RTC must be enabled, and PSG and 8253 must be disabled.

RTC Registers

Registers 00H-09H in BCD mode:

Register Bit Position Function Range
7 6 5 4 3 2 1 0
00H 0 10 Seconds Seconds Seconds 00–59
01H 0 10 Seconds Seconds Seconds Alarm 00–59
02H 0 10 Minutes Minutes Minutes 00–59
03H 0 10 Minutes Minutes Minutes Alarm 00–59
04H AM/PM 0 0 10 Hours Hours Hours 1–12 +AM/PM
0 10 Hours Hours 00–23
05H AM/PM 0 0 10 Hours Hours Hours Alarm 1–12 +AM/PM
0 10 Hours Hours 00–23
06H 0 0 0 0 0 Day Day 01–07
07H 0 0 10 Date Date Date 01–31
08H 0 0 0 10 Months Month Month 01–12
09H 10 Years Year Year 00–99

Registers 00H-09H in binary mode:

Register Bit Position Function Range
7 6 5 4 3 2 1 0
00H 0 0 Seconds Seconds 00–3B
01H 0 0 Seconds Seconds Alarm 00–3B
02H 0 0 Minutes Minutes 00–3B
03H 0 0 Minutes Minutes Alarm 00–3B
04H AM/PM 0 0 0 Hours Hours 01–0C +AM/PM
0 Hours 00–17
05H AM/PM 0 0 0 Hours Hours Alarm 01–0C +AM/PM
0 Hours 00–17
06H 0 0 0 0 0 Day Day 01–07
07H 0 0 0 Date Date 01–1F
08H 0 0 0 0 Month Month 01–0C
09H 0 Year Year 00–63

Control registers: 

 0Ah  Control A
       7   UIP Update in Progress (0=Stable in next 244us, 1=Time changes) (R)
       6-4 DV  Oscillator control (must be 2 for normal operation)
       3-0 RS  Rate Selector for IRQ pin (not used by SYMBiFACE II)
 0Bh  Control B
       7   SET  Stop clock, to be set/cleared before/after writing to [0h..9h]
       6   PIE  Periodic Interrupt Enable (see Control A, RS)
       5   AIE  Alarm Interrupt Enable
       4   UIE  Update-Ended Interrupt Enable (aka Seconds Interrupt)
       3   SQWE Square-Wave Enable (see Control A, RS)
       2   DM   Data Mode for [00h..09h] (0=BCD, 1=Binary)
       1   24H  24-Hour Mode             (0=12h with AM/PM, 1=24h)
       0   DSE  Daylight Saving Enable   (0=No, 1=Uses hardcoded timezone)
 0Ch  Control C (read-only, automatically reset to zero after reading)
       7   IRQF Interrupt Request Flag (1 on PIE,AIE,UIE, 0 after read) (R)
       6   PF   Periodic Interrupt Flag     (see Control A, RS)         (R)
       5   AF   Alarm Interrupt Enable Flag                             (R)
       4   UF   Update-Ended Interrupt Flag (aka Seconds Interrupt)     (R)
       3-0 0    Reserved (zero)
 0Dh  Control D (read-only)
       7   VRT  Valid RAM and Time (1=Okay, 0=Battery Low)              (R)
       6-0 0    Reserved (zero)

Non-Volatile RAM: 

 0Eh..3Fh battery backed RAM (HD146818, DS1287A, DS12887A and other chips)
 40h..7Fh battery backed RAM (only on DS12887A and newer chip variants)

Other chips

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