Rev. 1.0, 02/00, page 557 of 1141
26.2
Servo Port
26.2.1
Overview
This LSI is equipped with seventeen pins dedicated to the servo circuit and twenty-five pins
multiplexed with general-purpose ports. It also has an input amplifier to amplify CTL signals, a
CTL output amplifier, a CTL Schmitt comparator, and a CFG zero cross type comparator. The
CTL input amplifier allows gain adjustment by software. DFG and DPG signals, which control
the drum, can be input as separate signals or an overlapped signal.
SV1 and SV2 pins allow internal signals of the servo circuit to be output for monitoring. The
signals to be output can be selected out of eight kinds of signals. See the description of Servo
Monitor Control Register (SVMCR) in section 26.2.5, Register Description.
26.2.2
Block Diagram
1. DFG and DPG Input Circuit
The DFG and DPG input pins have on-chip Schmit circuits. Figure 26.2 shows the input
circuit of DFG and DPG.
DPG SW
DFG
DPG
DFG
DPG
DPG SW
Res+LPM
Figure 26.2 Input Circuit of DFG and DPG