Functional Description
MOTOROLA
SmartCard Interface Module (SIM)
25-7
and jump to MAIN_XMIT to transmit the next byte.
– When no transmit NACK error occurred and the FIFO is empty, return to the IDLE state.
– When the transmit NACK threshold is detected, stop the transmitter, set the XTE flag, and
jump to the IDLE state.
•
RTX_MAIN_XMIT
— The transmitter is operating normally in this state. The data in the shift register is shifting once
every transmit clock cycle. When the second to last bit of the current transmission is ready to
send, the state machine transitions to the RTX_LAST_XMIT state. This state is identical to the
MAIN_XMIT state except that it retransmits to the previously NACKed byte.
•
RTX_LAST_XMIT
— This state transmits the last bit of the current re-transmission and determines the next operation.
One of the following occurs:
– When GETU is non-zero, jump to the GUARD_WAIT state.
– When a transmit NACK error occurred and GETU contains a zero, jump to the
GUARD_WAIT state to check the transmit NACK threshold.
– When no transmit NACK error occurred, GETU contains a zero, and the FIFO is not empty,
load the shift register and jump to MAIN_XMIT to transmit the next byte.
– When no transmit NACK error occurred, GETU contains a zero, and the FIFO is empty,
jump to the IDLE state and set the TC bit in the XMT_STATUS register.
25.3.2.2 Transmit Shift Register
The transmit shift register is 11 bits wide and is controlled by the transmit state machine described
previously. The shift register moves data out at the transmit clock frequency (XMT_CK).
25.3.2.3 Transmit FIFO
The transmit FIFO is inside the transmitter block. The FIFO depth is 16 bytes for the MC9328MX1. Each
write to the transmit FIFO increments the transmit FIFO write pointer. Each time the transmit shift register
is loaded from the transmit FIFO, the transmit FIFO read pointer is incremented. When the read and write
pointers are equal, the transmit FIFO empty flag (TFE) is set. Software has no visibility of the transmit
FIFO pointers, however a transmit FIFO threshold value can be set to alert the software when the number
of bytes in the FIFO has reached a specified level. A read of the transmit FIFO register (XMT_BUF)
returns the last byte written to the FIFO. Writes to the transmit FIFO can occur at any time.
To flush the transmit FIFO, set the XMT_FLUSH bit in the RESET_CNTL register. A transmit NACK
threshold error (XTE) halts the transmitter and flushes the transmit FIFO. The flush operation resets the
transmit read and write pointers to equal values. Everything in the transmitter block is reset by the transmit
flush operation. Neither the control registers associated with the transmitter nor the transmit data threshold
flag (TDTF) in the transmit status register are cleared by the XMT_FLUSH operation.
25.3.2.4 Transmit Guard Time Generator
The transmit guard time generator is a counter that is clocked by the transmit clock to delay the beginning
of the next transmission and the setting of the TC bit in the XMT_STATUS register by a programmable
amount of transmit bit widths (ETUs). The duration of the count is controlled by the GUARD_CNTL
register (GETU). Figure 25-4 depicts three transmit operations that demonstrate the effect of the guard
time generator logic.
Содержание DragonBall MC9328MX1
Страница 68: ...1 12 MC9328MX1 Reference Manual MOTOROLA Introduction ...
Страница 86: ...2 18 MC9328MX1 Reference Manual MOTOROLA Signal Descriptions and Pin Assignments ...
Страница 116: ...3 30 MC9328MX1 Reference Manual MOTOROLA Memory Map ...
Страница 126: ...4 10 MC9328MX1 Reference Manual MOTOROLA ARM920T Processor ...
Страница 160: ...8 8 MC9328MX1 Reference Manual MOTOROLA System Control ...
Страница 272: ...13 32 MC9328MX1 Reference Manual MOTOROLA DMA Controller ...
Страница 281: ...Programming Model MOTOROLA Watchdog Timer Module 14 9 ...
Страница 282: ...14 10 MC9328MX1 Reference Manual MOTOROLA Watchdog Timer Module ...
Страница 300: ...15 18 MC9328MX1 Reference Manual MOTOROLA Analog Signal Processor ASP ...
Страница 438: ...18 16 MC9328MX1 Reference Manual MOTOROLA Serial Peripheral Interface Modules SPI 1 and SPI 2 ...
Страница 478: ...19 40 MC9328MX1 Reference Manual MOTOROLA LCD Controller ...
Страница 542: ...20 64 MC9328MX1 Reference Manual MOTOROLA Multimedia Card Secure Digital Host Controller Module MMC SD ...
Страница 574: ...21 32 MC9328MX1 Reference Manual MOTOROLA Memory Stick Host Controller MSHC Module ...
Страница 598: ...23 16 MC9328MX1 Reference Manual MOTOROLA Real Time Clock RTC ...
Страница 670: ...24 72 MC9328MX1 Reference Manual MOTOROLA SDRAM Memory Controller ...
Страница 726: ...25 56 MC9328MX1 Reference Manual MOTOROLA SmartCard Interface Module SIM ...
Страница 736: ...26 10 MC9328MX1 Reference Manual MOTOROLA General Purpose Timers ...
Страница 854: ...29 18 MC9328MX1 Reference Manual MOTOROLA I2C Module ...
Страница 900: ...30 46 MC9328MX1 Reference Manual MOTOROLA Synchronous Serial Interface SSI ...
Страница 942: ...32 26 MC9328MX1 Reference Manual MOTOROLA GPIO Module and I O Multiplexer IOMUX ...