System Integration Module (SIM60)
MOTOROLA
MC68360 USER’S MANUAL
6-27
the QUICC is in slave mode, assertion of the TS pin notifies the QUICC that an exter-
nal MC68040 cycle is beginning. Although the user typically configures the CONFIGx
pins for MC68040 companion mode, this configuration is not required. It is possible for
the QUICC to recognize an MC68040 cycle in any of the slave mode variations. (The
reason for the MC68040 companion mode configuration of the CONFIGx pins is to al-
low the bus arbitration pins to have their directions reversed while still in slave mode.)
6.8.6 Other Functionality in Slave Mode
Although the slave mode does enable a number of different pins on the system bus and
causes functional activities such as bus arbitration and interrupt handling to occur differ-
ently, if a feature is not cited as changing its behavior in slave mode (i.e., 98% of the features
on QUICC), then it is not impacted by slave mode and continues to operate normally.
6.9 PROGRAMMER’S MODEL
The SIM60 contains a number of registers, described in the following paragraphs. Their
locations and initial values may be found in Section 3 QUICC Memory Map.
6.9.1 Module Base Address Register (MBAR)
The MBAR is a 32-bit, memory-mapped, read-write register consisting of the high address
bits. Upon a total system reset, its value may be read as $0. The address of this register is
fixed at $03FF00 in CPU space (except in slave mode where it is located at $03FF04). See
6.8 Slave (Disable CPU32+) Mode for details.
CPU SPACE ONLY
BA31–BA13—Base Address
The base address field is the upper 19 bits of the MBAR, providing for block starting loca-
tions in increments of 8 Kbytes.
AS8–AS0—Address Space
The address space field allows particular address spaces to be masked, placing the 8K
module block into a particular address space(s). If an address space is masked, an ac-
cess to the register block location in that address space becomes an external access. The
module block is not accessed. The address space bits for non-040 type master are:
1. AS8—mask DMA space address space (FC3–FC0=1xxx)
2. AS7—mask CPU space address space (FC3–FC0=0111)
3. AS6—mask supervisor program address space (FC3–FC0=0110)
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
BA31
RESET:
0
BA30
BA29
BA28
BA27
BA26
BA25
BA24
BA23
BA22
BA21
BA20
BA19
BA18
BA17
BA16
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
15
14
13
12
0
11
0
10
0
9
8
7
6
5
4
3
2
1
0
V
BA15
RESET:
0
BA14
BA13
AS8
AS7
AS6
AS5
AS4
AS3
AS2
AS1
AS0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0