<ꢀ5ꢁꢀꢂꢃ<ꢀ.ꢁꢀꢂ
'PJCPEGFꢄ<ꢁꢀꢂꢄ/KETQRTQEGUUQT
ZiLOG
#5%+ꢄ%*#00'.ꢄ%10641.ꢄ4')+56'4ꢄ#ꢄꢈ%QPVKPWGFꢉ
/1&ꢁ
vious contents of 6&4' are held. 6' is cleared toꢅ0 in
+15612 mode during 4'5'6.
ꢐꢅꢀ→0QꢅRCTKV[
465ꢂꢅꢄ 4GSWGUVꢄ VQꢄ 5GPFꢄ %JCPPGNꢄ ꢂꢄ ꢌ$KVꢄ ꢉꢄ KPꢄ %06.#ꢂ
1PN[ꢍꢆꢄIf bit 4 of the System Configuration Register isꢅ0,
the465ꢀ/6:5pinexhibitsthe465ꢀ function.465ꢀ allows
the ASCI to control (start/stop) another communication de-
vices transmission (for example, by connecting to that de-
vice’s %65 input). 465ꢀ is essentially a 1-bit output port,
having no side effects on other ASCI registers or flags.
ꢐꢅꢄ→2CTKV[ꢅGPCDNGF
/1&ꢂ
ꢐꢅꢀ→ꢄꢅUVQRꢅDKV
ꢐꢅꢄ→ꢂꢅUVQRꢅDKVU
Bit 4 in %06.#ꢄ is used.
The data formats available based on all combinations of
/1&ꢂ, /1&ꢄ, and /1&ꢀ are indicated in Table 9.
%-#ꢄ&ꢅꢐꢅꢄꢇꢅ%-#ꢄꢌ6'0&ꢀꢅRKPꢅꢐꢅ6'0&ꢀ
6CDNG ꢏꢆ &CVCꢄ(QTOCVU
%-#ꢄ&ꢅꢐ ꢀ, %-#ꢄꢌ6'0&ꢀꢅRKPꢅꢐꢅ%-#ꢄ
/1&ꢇ /1&ꢁ /1&ꢂ &CVCꢄ(QTOCV
These bits are cleared toꢅ0on reset.
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
ꢄ
ꢀ
ꢄ
ꢀ
5VCTVꢅꢔꢅꢊꢅDKVꢅFCVCꢅꢔꢅꢄꢅUVQR
5VCTVꢅꢔꢅꢊꢅDKVꢅFCVCꢅꢔꢅꢂꢅUVQR
5VCTVꢅꢔꢅꢊꢅDKVꢅFCVCꢅꢔꢅRCTKV[ꢅꢔꢅ
ꢄꢅUVQR
/2$4ꢃ'(4ꢅꢄ/WNVKRTQEGUUQTꢄ$KVꢄ4GEGKXGꢃ'TTQTꢄ(NCIꢄ4GUGV
ꢌ$KVꢄꢋꢍꢆꢄWhen multiprocessor mode is enabled (/2 in
%06.$ꢅꢐꢅꢄ), /2$4, when read, contains the value of the
/2$ bit for the most recent receive operation. When written
toꢅ0, the '(4 function is selected to reset all error flags
(1840, (', 2' and $4- in the #5':6 Register) to 0.
/2$4/'(4 is undefined during 4'5'6.
ꢀ
ꢄ
ꢄ
5VCTVꢅꢔꢅꢊꢅDKVꢅFCVCꢅꢔꢅRCTKV[ꢅꢔꢅ
ꢂꢅUVQR
ꢄ
ꢄ
ꢄ
ꢀ
ꢀ
ꢄ
ꢀ
ꢄ
ꢀ
5VCTVꢅꢔꢅꢆꢅDKVꢅFCVCꢅꢔꢅꢄꢅUVQR
5VCTVꢅꢔꢅꢆꢅDKVꢅFCVCꢅꢔꢅꢂꢅUVQR
5VCTVꢅꢔꢅꢆꢅDKVꢅFCVCꢅꢔꢅRCTKV[ꢅꢔꢅ
ꢄꢅUVQR
/1&ꢇꢎꢄ ꢁꢎꢄ ꢂꢅꢄ #5%+ꢄ &CVCꢄ (QTOCVꢄ /QFGꢄ ꢇꢎꢁꢎꢂꢄ ꢌDKVUꢄ ꢇ ꢂꢍꢆ
These bits program the ASCI data format as follows.
ꢄ
ꢄ
ꢄ
5VCTVꢅꢔꢅꢆꢅDKVꢅFCVCꢅꢔꢅRCTKV[ꢅꢔꢅ
ꢂꢅUVQR
/1&ꢇ
ꢐꢅꢀ→ꢊ DKVꢅFCVC
ꢐꢅꢄ→ꢆꢅDKVꢅFCVC
ꢎꢂ
2ꢅ4ꢅ'ꢅ.ꢅ+ꢅ/ꢅ+ꢅ0ꢅ#ꢅ4ꢅ;
&5ꢀꢀꢁꢀꢀꢂꢃ</2ꢀꢂꢀꢀ
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