
W O R K I N G W I T H T H E C P U
R0: ID code and cache type status registers
86
Hardware Reference NS9215
The B bit is set to 0 at reset if the
BIGENDINIT
signal is low, and set to 1 if the
BIGENDINIT
signal is high.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
R 0 : I D c o d e a n d c a c h e t y p e s t a t u s r e g i s t e r s
Register R0 access the ID register, and cache type register. Reading from R0 returns
the device ID, and the cache type, depending on the
opcode_2
value:
The
CRm
field
SHOULD BE ZERO
when reading from these registers. This table shows
the instructions you can use to read register R0.
Writing to register R0 is
UNPREDICTABLE
.
R0: ID code
R0: ID code is a read-only register that returns the 32-bit device ID code. You can
access the ID code register by reading CP15 register R0 with the
opcode_2
field set to
any value other than 1 or 2. Note this example:
MRC p15, 0, Rd, c0, c0, {0, 3-7}; returns ID
This is the contents of the ID code register.
R0: Cache type
register
R0: Cache type is a read-only register that contains information about the size and
architecture of the instruction cache (ICache) and data cache (DCache) enabling
operating systems to establish how to perform operations such as cache cleaning
and lockdown. See “Cache features” on page 127 for more information about
cache.
opcode_2=0
ID value
opcode_2=1
instruction and data cache type
Function
Instruction
Read ID code
MRC p15,0,Rd,c0,c0,{0, 3-7}
Read cache type
MRC p15,0,Rd,c0,c0,1
Bits
Function
Value
[31:24]
ASCII code of implementer trademark
0x41
[23:20]
Specification revision
0x0
[19:16]
Architecture (ARMv5TEJ)
0x6
[15:4]
Part number
0x926
[3:0]
Layout revision
0x0
Summary of Contents for NS9215
Page 1: ...NS9215 Hardware Reference 90000847_C Release date 10 April 2008...
Page 3: ......
Page 4: ......
Page 26: ...26 Hardware Reference NS9215...
Page 44: ...P I N O U T 26 5 System clock 44 Hardware Reference NS9215 System clock drawing...
Page 52: ...P I N O U T 26 5 Power and ground 52 Hardware Reference NS9215...
Page 80: ...I O C O N T ROL M O D U L E Memory Bus Configuration register 80 Hardware Reference NS9215...
Page 136: ...WOR KI N G W I TH T H E C P U Noncachable instruction fetches 136 Hardware Reference NS9215...
Page 202: ...S Y S T E M C O N T RO L M OD U L E RTC Module Control register 202 Hardware Reference NS9215...
Page 354: ...E X T E R N A L D M A DMA Peripheral Chip Select register 354 Hardware Reference NS9215...
Page 472: ...R E A L TI M E C L O C K M O D U L E General Status register 472 Hardware Reference NS9215...
Page 512: ...TI M I NG Clock timing 512 Hardware Reference NS9215...
Page 515: ...PA CKA GING Processor Dimensions www digiembedded com 515...
Page 516: ...PA CKA GING Processor Dimensions 516 Hardware Reference NS9215...