Intel PXA255 Personal Computer User Manual


 
Intel® PXA255 Processor Developer’s Manual xiii
Contents
17.4.3 Autoflow Control .................................................................................................17-7
17.4.4 Auto-Baud-Rate Detection..................................................................................17-7
17.4.5 Slow Infrared Asynchronous Interface................................................................17-8
17.5 Register Descriptions.....................................................................................................17-10
17.5.1 Receive Buffer Register (RBR).........................................................................17-10
17.5.2 Transmit Holding Register (THR)......................................................................17-10
17.5.3 Divisor Latch Registers (DLL and DLH)............................................................17-10
17.5.4 Interrupt Enable Register (IER) ........................................................................17-11
17.5.5 Interrupt Identification Register (IIR).................................................................17-13
17.5.6 FIFO Control Register (FCR)............................................................................17-15
17.5.7 Receive FIFO Occupancy Register (FOR) .......................................................17-16
17.5.8 Auto-Baud Control Register (ABR)...................................................................17-17
17.5.9 Auto-Baud Count Register (ACR).....................................................................17-17
17.5.10 Line Control Register (LCR)..............................................................................17-18
17.5.11 Line Status Register (LSR)...............................................................................17-19
17.5.12 Modem Control Register (MCR) .......................................................................17-21
17.5.13 Modem Status Register (MSR).........................................................................17-23
17.5.14 Scratchpad Register (SCR) ..............................................................................17-24
17.5.15 Infrared Selection Register (ISR)......................................................................17-24
17.6 Hardware UART Register Summary..............................................................................17-25
Figures
2-1 Block Diagram ...........................................................................................................................2-2
2-2 Memory Map (Part One) — From 0x8000_0000 to 0xFFFF FFFF..........................................2-19
2-3 Memory Map (Part Two) — From 0x0000_0000 to 0x7FFF FFFF..........................................2-20
3-1 Clocks Manager Block Diagram ................................................................................................3-3
4-1 General-Purpose I/O Block Diagram .........................................................................................4-2
4-2 Interrupt Controller Block Diagram ..........................................................................................4-21
4-3 PWMn Block Diagram..............................................................................................................4-39
4-4 Basic Pulse Width Waveform ..................................................................................................4-43
5-1 DMAC Block Diagram................................................................................................................5-1
5-2 DREQ timing requirements........................................................................................................5-3
5-3 No-Descriptor Fetch Mode Channel State.................................................................................5-6
5-4 Descriptor Fetch Mode Channel State.......................................................................................5-8
5-5 Little Endian Transfers.............................................................................................................5-10
6-1 General Memory Interface Configuration...................................................................................6-2
6-2 SDRAM Memory System Example............................................................................................6-5
6-3 Static Memory System Example................................................................................................6-6
6-4 External to Internal Address Mapping Options ........................................................................6-19
6-5 Basic SDRAM Timing Parameters...........................................................................................6-29
6-6 SDRAM_Read_diffbank_diffrow..............................................................................................6-29
6-7 SDRAM_read_samebank_diffrow ...........................................................................................6-30
6-8 SDRAM_read_samebank_samerow .......................................................................................6-30
6-9 SDRAM_write..........................................................................................................................6-31
6-10 SDRAM 4-Beat Read/ 4-Beat Write To Different Partitions.....................................................6-31
6-11 SDRAM 4-Beat Write / 4-Write Same Bank, Same Row.........................................................6-32
6-12 SMROM Read Timing Diagram Half-Memory Clock Frequency .............................................6-39
6-13 Burst-of-Eight Synchronous Flash Timing Diagram (non-divide-by-2 mode) ..........................6-41