
Table of Contents
ii
5.2.11 RegisterAddress Mapping Register (RAMP) 0xE030....................................................................... 5-14
6. Clocks..................................................................................................................................................................... 6-1
6.1 TX4925 Clock Signals................................................................................................................................... 6-1
6.2 Power-Down Mode........................................................................................................................................ 6-5
6.2.1 Halt Mode and Doze Mode................................................................................................................... 6-5
6.2.2 Power Reduction for Peripheral Modules ............................................................................................. 6-5
6.2.3 Power-Down Mode ............................................................................................................................... 6-5
6.3 Power-On Sequence....................................................................................................................................... 6-6
7. External Bus Controller.......................................................................................................................................... 7-1
7.1 Features.......................................................................................................................................................... 7-1
7.2 Block Diagram............................................................................................................................................... 7-2
7.3 Detailed Explanation...................................................................................................................................... 7-3
7.3.1 External Bus Control Register............................................................................................................... 7-3
7.3.2 Global/Boot-up Options........................................................................................................................ 7-4
7.3.3 Address Mapping .................................................................................................................................. 7-5
7.3.4 External Address Output ....................................................................................................................... 7-6
7.3.5 Data Bus Size........................................................................................................................................ 7-7
7.3.6 Access Modes........................................................................................................................................ 7-9
7.3.7 Access Timing..................................................................................................................................... 7-13
7.3.8 Clock Options...................................................................................................................................... 7-19
7.3.9 PCMCIA mode.................................................................................................................................... 7-20
7.4 Register ........................................................................................................................................................ 7-24
7.4.1 External Bus Channel Control Register (EBCCRn) 0x9000 (ch. 0), 0x9008 (ch. 1)
0x9010 (ch. 2), 0x9018 (ch. 3) 0x9020 (ch. 4), 0x9028 (ch. 5) 0x9030 (ch. 6), 0x9038 (ch. 7)....... 7-25
7.4.2 External Bus Base Address Register (EBBARn) 0x9000 (ch. 0), 0x9008 (ch. 1) 0x9010 (ch. 2),
0x9018 (ch. 3) 0x9020 (ch. 4), 0x9028 (ch. 5) 0x9030 (ch. 6), 0x9038 (ch. 7) ................................ 7-28
7.5 Timing Diagrams ......................................................................................................................................... 7-29
7.5.1 UAE Signal ......................................................................................................................................... 7-30
7.5.2 Normal Mode Access (Single, 32-bit Bus).......................................................................................... 7-32
7.5.3 Normal Mode Access (Burst, 32-bit Bus) ........................................................................................... 7-36
7.5.4 Normal Mode Access (Single, 16-bit Bus).......................................................................................... 7-38
7.5.5 Normal Mode Access (Burst, 16-bit Bus) ........................................................................................... 7-42
7.5.6 Normal Mode Access (Single, 8-bit Bus)............................................................................................ 7-44
7.5.7 Normal Mode Access (Burst, 8-bit Bus) ............................................................................................. 7-47
7.5.8 Page Mode Access (Burst, 32-bit Bus)................................................................................................ 7-49
7.5.9 External ACK Mode Access (32-bit Bus) ...........................................................................................7-51
7.5.10 READY Mode Access (32-bit Bus)..................................................................................................... 7-57
7.6 Flash ROM, SRAM Usage Example ........................................................................................................... 7-59
8. DMA Controller...................................................................................................................................................... 8-1
8.1 Features.......................................................................................................................................................... 8-1
8.2 Block Diagram............................................................................................................................................... 8-2
8.3 Detailed Explanation...................................................................................................................................... 8-3
8.3.1 Transfer Mode....................................................................................................................................... 8-3
8.3.2 On-chip Registers.................................................................................................................................. 8-3
8.3.3 External I/O DMATransfer Mode ........................................................................................................ 8-4
8.3.4 Internal I/O DMATransfer Mode.......................................................................................................... 8-7
8.3.5 Memory-Memory Copy Mode.............................................................................................................. 8-7
8.3.6 Memory Fill Transfer Mode.................................................................................................................. 8-8
8.3.7 Single Address Transfer ........................................................................................................................ 8-8
8.3.8 Dual Address Transfer......................................................................................................................... 8-10
8.3.9 DMATransfer ..................................................................................................................................... 8-15
8.3.10 Chain DMA Transfer........................................................................................................................... 8-16
8.3.11 Dynamic Chain Operation................................................................................................................... 8-18
8.3.12 Interrupts............................................................................................................................................. 8-19
8.3.13 Transfer Stall Detection Function........................................................................................................ 8-19
8.3.14 Arbitration Among DMA Channels..................................................................................................... 8-20