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Zynq-7000 AP SoC Technical Reference Manual www.xilinx.com 695
UG585 (v1.11) September 27, 2016
Chapter 25: Clocks
25.8 Trace Port Clock
The trace port clock is used to clock the TPIU and trace buffer when the MIO interface is chosen and
must be twice the frequency of the desired TPIU clock. The TPIU clock frequency must be chosen to
be fast enough to allow the trace port to keep up with the amount of data being traced, but slow
enough to meet the dynamic characteristics of the data output buffers of the TPIU. To allow some
flexibility, the trace clock is generated from a divided PLL output for MIO. When the trace port is
routed through EMIO, the EMIOTRACECLK input is used to clock the TPIU as shown in Figure 25-12.
25.9 Register Overview
An overview of the PS clock subsystem registers is shown in Table 25-5.
X-Ref Target - Figure 25-12
Figure 25-12: Trace Port Clock Generation
UG585_c25_11_072512
IO PLL
ARM PLL
DDR PLL
EMIOTRACECLK
Clock
Gate
Glitch-Free
6-bit
Programmable
Divider
Glitch-Free
DBG_CLK_CTRL Register Bit Fields
0
1
Debug
Subsystem
Not
Glitch-
Free
1
0
Glitch-
Free
Glitch-
Free
0
1
[6][5][6] [0][13:8]
Table 25-5: Clock Generation Register Overview
Register Description Comments
PLL
PLL_STATUS PLL status
ARM_PLL_CTRL CPU PLL control
Control registers include:
Reset, power-down, bypass
Divisor(s)
Configuration registers include:
PLL control parameters (see Table 25-6)
ARM_PLL_CFG CPU PLL configuration
DDR_PLL_CTRL DDR PLL control
DDR_PLL_CFG DDR PLL configuration
IO_PLL_CTRL I/O PLL control
IO_PLL_CFG I/O PLL configuration
CPU, DDR and Interconnect
ARM_CKL_CTRL CPU clock control