AMD Geode SC1201 - Manual (Page 82)

82 AMD Geode™ SC1200/SC1201 Processor Data Book
General Configuration Block 32579B
Table 4-4. High-Resolution Timer Registers
Bit Description
Offset 08h-0Bh TIMER Value Register - TMVALUE (RO) Reset Value: xxxxxxxxh
This register contains the current value of the High-Resolution Timer.
31:0 Current Timer Value.
Offset 0Ch TIMER Status Register - TMSTS (R/W) Reset Value: 00h
This register supplies the High-Resolution Timer status information.
7:1 Reserved.
0 TMSTS (TIMER Status). This bit is set to 1 when the most significant bit (bit 31) of the timer changes from 1 to 0. It is
cleared to 0 upon system reset or when 1 is written by software to this bit.
Offset 0Dh TIMER Configuration Register - TMCNFG (R/W) Reset Value: 00h
This register enables the High-Resolution Timer interrupt; selects the Timer clock; and disables the 27 MHz internal clock during low
power states.
7:3 Reserved.
2 TM27MPD (TIMER 27 MHz Power Down). This bit is cleared to 0 when POR# is asserted or when the GX1 module de-
asserts its internal SUSPA# signal (i.e., on SUSPA# rising edge). See Section 4.4.2.1 "Usage Hints" on page 81.
0: 27 MHz input clock is enabled.
1: 27 MHz input clock is disabled when the GX1 module asserts its internal SUSPA# signal.
1 TMCLKSEL (TIMER Clock Select).
0: Count-up timer uses the oscillator clock divided by 27.
1: Count-up timer uses the oscillator clock, 27 MHz clock.
0 TMEN (TIMER Interrupt Enable).
0: High-Resolution Timer interrupt is disabled.
1: High-Resolution Timer interrupt is enabled.
Offset 0Eh-0Fh Reserved - RSVD