SH7713 Datasheet, PDF (547/904 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperHTM RISC engine Family / SH7700 Series

Section 15 Realtime Clock (RTC)
15.2 Input/Output Pins
Table 15.1 shows the RTC pin configuration.
Table 15.1 Pin Configuration
Pin Name
Abbreviation I/O Function
RTC external clock
EXTAL2
I Connects crystal to RTC oscillator*¹
RTC crystal
XTAL2
O Connects crystal to RTC oscillator*¹
RTC oscillator power supply
VccQ-RTC — Dedicated power-supply pin for RTC*²
RTC oscillator ground
VssQ-RTC — Dedicated GND pin for RTC
Note:
1. Pull up (VccQ-RTC) the EXTAL2 pin, and open (NC) the XTAL2 pin when the realtime
clock (RTC) is not used.
2. RTC in this LSI does not operate even if VccQ-RTC is turned on. The crystal oscillator
circuit for RTC operates with VccQ-RTC. The control circuit and the RTC counter
operate with Vcc (common to the internal circuit). Therefore, all power supplies other
than VccQ-RTC should always be turned on even if only RTC operates.
15.3 Register Descriptions
The RTC has the following registers. Refer to section 23, List of Registers, for more details on the
address and access size.
• 64-Hz counter (R64CNT)
• Second counter (RSECCNT)
• Minute counter (RMINCNT)
• Hour counter (RHRCNT)
• Day of week counter (RWKCNT)
• Date counter (RDAYCNT)
• Month counter (RMONCNT)
• Year counter (RYRCNT)
• Second alarm register (RSECAR)
• Minute alarm register (RMINAR)
• Hour alarm register (RHRAR)
• Day of week alarm register (RWKAR)
• Date alarm register (RDAYAR)
• Month alarm register (RMONAR)
• Year alarm register (RYRAR)
Rev.1.50 Aug. 30, 2006 Page 507 of 860
REJ09B0288-0150