Area Overview; Area Division - Renesas HD6417641 Hardware Manual

32-bit risc microcomputer superh risc engine family / sh7641 series
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Name
WE0
RASU
RASL
CASU
CASL
CKE
FRAME
WAIT
BREQ
BACK
MD3
12.3

Area Overview

12.3.1

Area Division

In the architecture of this LSI, both logical spaces and physical spaces have 32-bit address spaces.
The cache access method is shown by the upper three bits. For details see section 7, Cache. The
remaining 29 bits are used for division of the space into ten areas (address map 1) or eight areas
(address map 2) according to the MAP bit in the CMNCR register setting. The BSC performs
control for this 29-bit space.
As listed in tables 12.2 and 12.3, this LSI can connect various memories to eight areas or six areas,
and it outputs chip select signals (CS0, CS2 to CS4, CS5A, CS5B, CS6A, and CS6B) for each of
them. CS0 is asserted during area 0 access; CS5A is asserted during area 5A access when address
map 1 is selected; and CS5B is asserted when address map 2 is selected. Also CS6A is asserted
during area 6A access when address map 1 is selected; and CS6B is asserted when address map 2
is selected.
I/O
Function
Output
Indicates that D7 to D0 are being written to.
Connected to the byte select signal when a byte-selection SRAM is
connected.
Functions as the selection signals for D7 to D0 when SDRAM is
connected.
Connects to RAS pin when SDRAM is connected.
Output
Connects to CAS pin when SDRAM is connected.
Output
Output
Clock enable for SDRAM
Output
Functions as FRAME signal when connected to burst MPX-IO
interface
Input
External wait input
Input
Bus request input
Output
Bus enable input
Input
MD3: Select area 0 bus width (16/32 bits)
Section 12 Bus State Controller (BSC)
Rev. 4.00 Sep. 14, 2005 Page 273 of 982
REJ09B0023-0400

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