TNETV2501INPGF datasheet(106/197 Pages) TI1

106 / 197 page

Functional Overview

106

December 2002 − Revised November 2008

SPRS206K

3.13 Internal Ports and System Registers

The 5501 includes three internal ports that interface the CPU core with the peripheral modules. Although these

ports cannot be directly controlled by user code, the registers associated with each port can be used to monitor

a number of error conditions that could be generated through illegal operation of the 5501. The port registers

are described in the following sections.

The 5501 also includes two registers that can be used to monitor and control several aspects of the interface

between the CPU and the system-level peripherals, these registers are also described in the following

sections.

3.13.1

XPORT Interface

The XPORT interfaces the CPU core to all peripheral modules. The XPORT will generate bus errors for invalid

accesses to any registers that fall under the ranges shown in Table 3−47. The INTERREN bit of the XPORT

Configuration Register (XCR) controls the bus error feature of the XPORT. The INTERR bit of the XPORT Bus

Error Register (XERR) is set to “1” when an error occurs during an access to a register listed in Table 3−47.

The EBUS and DBUS bits can be used to distinguish whether the error occurred during a write or read access.

Table 3−47. I/O Addresses Under Scope of XPORT

I/O ADDRESS RANGE

0x0000−0x03FF

0x1400−0x17FF

0x2000−0x23FF

The PERITO bit of the XERR is used to indicate that a CPU, DMA, or HPI access to a disabled/idled peripheral

module has generated a time-out error. The time-out error feature is enabled through the PERITOEN bit of

the Time-Out Control Register (TOCR). A time-out error is generated when 512 clock cycles pass without a

response from the peripheral register.

The XPORT can be placed into idle by setting the XPORTI bit of the Idle Control Register (ICR) and executing

the IDLE instruction. When the XPORT is in idle, it will stop accepting new peripheral module requests and

it will also not check for internal I/O bus errors. If there is a request from the CPU core or a peripheral module,

the XPORT will not respond and hang. The ICR register will generate a bus error if the XPORT is idled without

the CPU or Master Port domains being in idle mode.

TNETV2501INPGF 데이터시트(PDF) 106 Page - Texas Instruments