User manual

Table Of Contents
Zynq-7000 AP SoC Technical Reference Manual www.xilinx.com 735
UG585 (v1.11) September 27, 2016
Chapter 29: On-Chip Memory (OCM)
29.1.1 Block Diagram
29.1.2 Features
Key features of the OCM include:
•On-chip 256KB RAM
On-chip 128 KB BootROM (not user visible)
Two AXI 3.0, 64-bit slave interfaces
Low latency path for CPU/ACP reads to OCM (CPU at 667 MHz – minimum 23 cycles)
Round-robin pre-arbitration between read and write AXI channels on OCM-interconnect port
(non-CPU port)
Fixed priority arbitration between the CPU/ACP (via SCU) and OCM-interconnect AXI ports
Supports full AXI 64-bit bandwidth of simultaneous read and write commands (with optimal
alignment restrictions) on the OCM interconnect port
Random access supported to RAM from AXI masters
X-Ref Target - Figure 29-1
Figure 29-1: OCM Block Diagram
UG585_c29_01_042512
Parity
Generation
& Checking
256 KB
RAM
Arbiter
Registers
4-port Mem
Controller
SCU
AXI64 WrData
OCM Switch
AXI64 WrData
OCM Switch
AXI64 RdCmd
OCM Switch
AXI64 WrCmd
SCU
AXI64 WrCmd
SCU
AXI64 RdCmd
APB I/F
OCM Switch
AXI64 Bresp
OCM Switch
AXI64 RdData
SCU
AXI64 Bresp
SCU
AXI64 RdData
IRQ