Contents
vii
CHAPTER 7
HOST INTERFACE PORT
7.1
OVERVIEW ........................................................................................ 7–1
7.2
HIP PIN SUMMARY ......................................................................... 7–2
7.3
HIP FUNCTIONAL DESCRIPTION............................................... 7–4
7.4
HIP OPERATION .............................................................................. 7–6
7.4.1
Polled Operation .......................................................................... 7–7
7.4.1.1
HIP Status Synchronization ................................................. 7–8
7.4.2
Interrupt-Driven Operation ....................................................... 7–9
7.4.3
HDR Overwrite Mode................................................................. 7–9
7.4.4
Software Reset ............................................................................ 7–10
7.5
HIP INTERRUPTS ........................................................................... 7–10
7.6
HOST INTERFACE TIMING ......................................................... 7–11
7.7
BOOT LOADING THROUGH THE HIP ..................................... 7–16
CHAPTER 8
ANALOG INTERFACE
8.1
OVERVIEW ........................................................................................ 8–1
8.2
A/D CONVERSION ......................................................................... 8–2
8.2.1
Analog Input ................................................................................ 8–2
8.2.2
ADC
........................................................................................ 8–3
8.2.2.1
Decimation Filter ................................................................... 8–4
8.2.2.2
High Pass Filter ...................................................................... 8–5
8.3
D/A CONVERSION ......................................................................... 8–6
8.3.1
DAC
........................................................................................ 8–6
8.3.1.1
High Pass Filter ...................................................................... 8–6
8.3.1.2
Interpolation Filter ................................................................. 8–7
8.3.1.3
Analog Smoothing Filter & Programmable Gain Amp. .. 8–8
8.3.2
Differential Output Amplifier.................................................... 8–8
8.4
OPERATING THE ANALOG INTERFACE .................................. 8–9
8.4.1
Memory-Mapped Control Registers ......................................... 8–9
8.4.1.1
Analog Control Register ....................................................... 8–9
8.4.1.2
Analog Autobuffer/Powerdown Register ....................... 8–10
8.4.2
Memory-Mapped Data Registers ............................................ 8–11
8.4.3
ADC & DAC Interrupts ............................................................ 8–12
8.4.3.1
Autobuffering Disabled ...................................................... 8–12
8.4.3.2
Autobuffering Enabled ....................................................... 8–13
8.5
CIRCUIT DESIGN CONSIDERATIONS ...................................... 8–16
8.5.1
Analog Signal Input .................................................................. 8–16
8.5.2
Analog Signal Output ............................................................... 8–18
8.5.3
Voltage Reference Filter Capacitance ..................................... 8–19