SC2200 NSC [National Semiconductor], SC2200 Datasheet - Page 92

• Manufacturer Part Number: SC2200
• Description: Thin Client On a Chip
• Manufacturer: NSC [National Semiconductor]

www.national.com
General Configuration Block
Offset 08h-0Bh
This register contains the current value of the High-Resolution Timer.
Offset 0Ch
This register supplies the High-Resolution Timer status information.
Offset 0Dh
This register enables the High-Resolution Timer interrupt; selects the Timer clock; and disables the 27 MHz internal clock during low
power states.
Offset 0Eh-0Fh
31:0
7:1
7:3
Bit
0
2
1
0
Description
Current Timer Value.
Reserved
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.
Reserved.
TM27MPD (TIMER 27 MHz Power Down). This bit is cleared to 0 when POR# is asserted or when the GX1 module deas-
serts its internal SUSPA# signal (i.e., on SUSPA# rising edge). See Section 3.4.2.1 "Usage Hints" on page 91.
0: 27 MHz input clock is enabled.
1: 27 MHz input clock is disabled when the GX1 module asserts its internal SUSPA# signal.
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.
TMEN (TIMER Interrupt Enable).
0: High-Resolution Timer interrupt is disabled.
1: High-Resolution Timer interrupt is enabled.
Table 3-4. High-Resolution Timer Registers
TIMER Configuration Register - TMCNFG (R/W)
TIMER Value Register - TMVALUE (RO)
(Continued)
TIMER Status Register - TMSTS (R/W)
Reserved - RSVD
92
Reset Value: xxxxxxxxh
Reset Value: 00h
Reset Value: 00h
Revision 3.0