STC3500 Datasheet, PDF (41/48 Pages) Connor-Winfield Corporation – INTEGRATED - STRATUM 3 TIMING SOURCE

Application Notes continued
Register Access Manual Control
In Register Control Mode, far more internal device information is available. However, Operational mode and Reference
Selection may still be performed manually. The control configuration for this mode of operation is shown in Figure 13:
Register Access Manual Control Interfaces
Figure 13
Reset
BITS output
frequency select
0 = 2.048 MHz
1 = 1.544 MHz
Reset
BITS_Sel
STC3500
HM_Ref
LOS
Bus Mode:
1 = Parallel
Bmode
I/O
0 = SPI
Bus Interface
CS
ALE or SCLK
R/W or SDI
RDY or SDO
8 ^AD0-7
Interrupt
INTR
LOL
Hold_Avail
INTR
Outputs
(Optional Use)
In Register Access Manual Control Operation, the hardware control pin, HM_Ref, is tied low.
Reset may be pulled low for a minimum of 100nS during chip start-up (or any other desired time) to initialize the full
device state.
Following any reset, device configuration data must be pumped, either automatically from the external EEPROM, or by
the application through the bus interface (see Application Notes, General, Configuration Data section). Tie Dmode
“High” for EEPROM pump, and “Low” for register pump.
If the optional EEPROM is equipped, EEPROM data may be read or written via the bus interface. See Application
Notes, General, Reading and Writing EEPROM section.
The BITS clock output frequency is selected by the BITS_Sel pin. When BITS_Sel = 1, the BITS frequency is 1.544
MHz and when BITS_Sel = 0, the BITS frequency is 2.048 MHz
Bus access may be either in parallel or SPI mode. Bmode is connected “high” for parallel bus and “low” for SPI
operation. Parallel bus operation uses CS, ALE, R/W, RDY, and AD0-7, as described in the Register Control section,
Figures 3 and 4, and Table 6. SPI uses CS, SCLK, SDI, and SDO, as described in the Register Control section, Figures
5 and 6, and Table 7.
Preliminary Data Sheet: TM060 Page 41 of 48 Rev: P06 Date: 11/22/04
© Copyright 2001 The Connor-Winfield Corp. All Rights Reserved Specifications subject to change without notice