System Control Registers
292
SPRUH22I – April 2012 – Revised November 2019
Copyright © 2012–2019, Texas Instruments Incorporated
System Control and Interrupts
Table 1-182. C28 Flash Semaphore Field Descriptions (continued)
Bit
Field
Value
Description
1-0
SEM
0
Pump Access Request Semaphore from the C28
• A value of “00”, “10”, “11” gives ownership to the M3
• A value of “01” gives ownership to the C28.
• The following are the only state transitions allowed on these bits.
–
"00","11" -> "01"
–
"00","11" -> "10"
• "10" -> "00","11" (This can only happen from a C28x write to these bits to relinquish its
ownership)
• State transitions from "00"
→
"11" and "11"
→
"00" are allowed by design. However these
transitions will not result in change in ownership.
1.13.12.7 C28 Clock Semaphore Register
Figure 1-171. C28 Clock Semaphore Register
31
16
KEY
R=0/W
15
4
3
2
1
0
KEY
Reserved
SEM
R=0/W
R-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -
n
= value after reset
Table 1-183. C28 Clock Semaphore Field Descriptions
Bit
Field
Value
Description
31-4
KEY
0
Writing the value 0xE318C59 will allow writes to the SEM bits or writes are ignored. Reads will
return 0.
Note:
This is to prevent spurious writes to the semaphore bits.
3-2
Reserved
Reserved
1-0
SEM
0
Clock Control Access Request from the C28
• A value of “00”, “10”, “11” gives ownership to the M3
• A value of “01” gives ownership to the C28.
• The following are the only state transitions allowed on these bits.
–
"00","11" -> "01"
–
"00","11" -> "10"
• "10" -> "00","11" (This can only happen from a C28x write to these bits to relinquish its
ownership)
• State transitions from "00"
→
"11" and "11"
→
"00" are allowed by design. However these
transitions will not result in change in ownership.