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Bus Controller (BC)
8-60
8.13.12
8-bit Bus in Asynchronous Mode and in Address/Data Multiplex Mode
By setting the mode through the MMOD1 and 0 pins and the EXMOD1 and 0 pins, blocks 0 to 3 use multiplex pins
for the memory address and memory data signals (pins ADM15 to 0).
8-bit bus mode is set for block 0 by setting the mode through the MMOD1 and 0 pins and the EXMOD1 and 0 pins,
and for blocks 1 to 3 by setting the BnBW bit to “0” in the corresponding memory control register. In 8-bit bus
mode, half-word access (16 bits) is performed by means of two external accesses, with A[0] = “0” for the low-order
byte and A[0] = “1” for the high-order byte. Word access (32 bits) is performed by means of four accesses, with
A[1:0] = “00”, A[1:0] = “01”, A[1:0] = “10”, and A[1:0] = “11”, starting from the low-order side. Note that the
low-order 8 bits (D7 to 0) are used for the data bus.
Asynchronous mode is used for accessing external memory at high speed; the address signals, CSn signals, etc., are
output asynchronously with SYSCLK but in synchronization with the internal MCLK. In asynchronous mode,
accesses are all by fixed wait insertion.
The various parameters for external memory access are set in memory control registers 0 to 3, corresponding to
each block.
Fig. 8-13-30 is the timing chart in the case of a half-word access using an “8-bit bus in asynchronous mode, in
address/data multiplex mode.”
As shown in each timing chart, the ADM15 to 0 pins go to “Hi-Z” or the undefined output state while CSn is
negated in address/data multiplex mode. When the bus authority is released, the ADM15 to 0 pins are either pulled
up or go to “Hi-Z”, depending on the setting of the I/O port output mode register.
Note that when writing, WE0 is asserted and the data is output on ADM7 to 0.
Note: For details on the mode settings, refer to Table 8-9-1, “Mode Settings by the BC External Pins.”
Note: “0” (low level) is output on pins A23 to 16 (A23 also serves as CS3) while the ADM15 to 0 pins function as
data pins. Therefore, refer to 3. in section 8.16, “Cautions,” regarding the use of these pins.
Содержание MN103001G/F01K
Страница 1: ...MICROCOMPUTER MN1030 MN103001G F01K LSI User s Manual Pub No 23101 050E ...
Страница 2: ......
Страница 4: ......
Страница 6: ......
Страница 7: ...14 A D Converter 15 I O Ports 16 Internal Flash Memory 17 Ordering Mask ROM Appendix 14 15 16 17 ...
Страница 8: ......
Страница 9: ...Table of Contents List of Figures and Tables 0 ...
Страница 26: ...xviii ...
Страница 27: ...1 0 1 General Specifications ...
Страница 35: ...2 CPU 2 ...
Страница 57: ...3 Extension Instruction Specifications 3 ...
Страница 96: ...Extension Instruction Specifications 3 40 ...
Страница 97: ...4 Memory Modes 3 4 ...
Страница 102: ...Memory Modes 4 6 ...
Страница 103: ...5 Operating Mode 5 ...
Страница 107: ...6 Clock Generator 6 13 ...
Страница 111: ...7 Internal Memory 7 ...
Страница 114: ...Internal Memory 7 4 ...
Страница 115: ...8 Bus Controller BC 8 ...
Страница 189: ...9 Interrupt Controller 9 ...
Страница 220: ...Interrupt Controller 9 32 ...
Страница 221: ...10 8 bit Timers 9 10 ...
Страница 254: ...8 bit Timers 10 34 ...
Страница 255: ...11 16 bit Timers 11 ...
Страница 292: ...16 bit Timers 11 38 ...
Страница 293: ...12 Watchdog Timer 11 12 ...
Страница 302: ...Watchdog Timer 12 10 ...
Страница 303: ...13 Serial Interface 13 ...
Страница 354: ...Serial Interface 13 52 ...
Страница 355: ...14 A D Converter 14 ...
Страница 367: ...15 I O Ports 15 ...
Страница 431: ...16 Internal Flash Memory 16 ...
Страница 439: ...17 17 Ordering Mask ROM ...
Страница 442: ...Ordering Mask ROM 17 4 ...
Страница 443: ...Appendix ...