3.2.3
External Clock Source
The recommended method of connecting an external clock is illustrated in Figure 3-4. The external clock
source is connected to XTAL and the EXTAL pin is grounded. Set OCCS_COHL bit high when using an
external clock source as well.
Note: When using an external clocking source
XTAL
EXTAL
with this configuration, the input “CLKMODE”
should be high and the COHL bit in the OSCTL
register should be set to 1.
V
External
Clock
SS
Figure 3-4 Connecting an External Clock Signal Register
3.3 Registers
When referring to the register definitions for the OCCS in the 56F8300 Peripheral User Manual, use the
register definitions without the internal Relaxation Oscillator, since the 56F8355/56F8155 devices do
NOT contain this oscillator.
Part 4 Memory Map
4.1 Introduction
The 56F8355 and 56F8155 devices are 16-bit motor-control chips based on the 56800E core. These parts
use a Harvard-style architecture with two independent memory spaces for Data and Program. On-chip
RAM and Flash memories are used in both spaces.
This section provides memory maps for:
•
•
Program Address Space, including the Interrupt Vector Table
Data Address Space, including the EOnCE Memory and Peripheral Memory Maps
On-chip memory sizes for each device are summarized in Table 4-1. Flash memories’ restrictions are
identified in the “Use Restrictions” column of Table 4-1.
56F8355 Technical Data, Rev. 12
36
Freescale Semiconductor
Preliminary
FREESCALE [ Freescale ]
